LHASA, Tibet — They come by new high-altitude trains, four a day, cruising 1,200 miles past snow-capped mountains. And they come by military truck convoy, lumbering across the roof of the world.

Han Chinese workers, investors, merchants, teachers and soldiers are pouring into remote Tibet. After the violence that ravaged this region in 2008, China’s aim is to make Tibet wealthier — and more Chinese.

Chinese leaders see development, along with an enhanced security presence, as the key to pacifying the Buddhist region. The central government invested $3 billion in the Tibet Autonomous Region last year, a 31 percent increase over 2008. Tibet’s gross domestic product is growing at a 12 percent annual rate, faster than the robust Chinese national average.

Simple restaurants located in white prefabricated houses and run by ethnic Han businesspeople who take the train have sprung up even at a remote lake north of Lhasa. About 1.2 million rural Tibetans, nearly 40 percent of the region’s population, have been moved into new residences under a “comfortable housing” program. And officials promise to increase tourism fourfold by 2020, to 20 million visitors a year.

But if the influx of money and people has brought new prosperity, it has also deepened the resentment among many Tibetans. Migrant Han entrepreneurs elbow out Tibetan rivals, then return home for the winter after reaping profits. Large Han-owned companies dominate the main industries, from mining to construction to tourism.

“Why did I come here? To make money, of course!” said Xiong Zhahua, a migrant from Sichuan Province who spends five months a year running a restaurant on the shores of chilly Nam Tso, the lake north of Lhasa.

A rare five-day official tour of Tibet, though carefully managed by the Chinese Foreign Ministry, provided a glimpse of life in the region during a period of tight political and military control.

Tibet is more stable after security forces quelled the worst uprising against Chinese rule in five decades. But the increased ethnic Han presence — and the uneven benefits of Han-led investment — have kept the region on edge.

Some Chinese officials acknowledge the disenfranchisement of Tibetans, though they defend the right of Han to migrate here.

“The flow of human resources follows the rule of market economics and is also indispensable for the development of Tibet,” Hao Peng, vice chairman and deputy party secretary of the region, said at a news conference with a small group of foreign journalists. But the current system “may have caused an imbalanced distribution,” he said. “We are taking measures to solve this problem.”

The government bars foreign reporters from traveling independently in Tibet. Journalists on the tour were brought to several development projects by ministry officials, but were occasionally able to interview locals on their own. Tibetans interviewed independently expressed fear of the security forces and spoke on the condition of anonymity.

One high school student complained that Tibetans could not compete for jobs with Han migrants who arrived with high school diplomas. “Tibetans just get low-end jobs,” he said.

Chinese officials say Tibetans make up more than 95 percent of the region’s 2.9 million people, but refuse to give estimates on Han migrants, who are not registered residents. In the cities of Lhasa and Shigatse, it is clear that Han neighborhoods are dwarfing Tibetan areas.

Resentment of the Han exploded during the March 2008 rioting — Tibetans in Lhasa burned and looted hundreds of Han and ethnic Hui shops; at least 19 people died, most of them Han civilians, the Chinese government said. Han security forces then cracked down on Tibetans across the plateau.

Robert Barnett, a scholar of Tibet at Columbia University, said the goal of maintaining double-digit growth in the region had worsened ethnic tensions.

“Of course, they achieved that, but it was disastrous,” he said. “They had no priority on local human resources, so of course they relied on outside labor, and sucked in large migration into the towns.”

Now, a heavy security presence is needed to keep control of Lhasa. Around the Barkhor, the city’s central market, paramilitary officers in riot gear, all ethnic Han, march counterclockwise around the sacred Jokhang Temple, against the flow of Tibetan pilgrims. Armed men stand on rooftops near the temple.

Limits on religious freedom have been a major cause of discontent. In the Jokhang itself, and in the Potala Palace, the imposing white-walled winter fortress of the Dalai Lamas, images of the exiled 14th Dalai Lama have been banned. Pilgrims carry the Dalai Lama’s photograph in hidden lockets or amulets. As the pilgrims circle the Potala, a loudspeaker in a small park blares Communist Party propaganda: “We are part of a Chinese nation contributing to a great future — we are Chinese people.”

Development programs are sometimes well received, and sometimes they create resentment. Since 2006, the Tibetan government has mandated that Tibetan farmers, herders and nomads use government subsidies to build new homes closer to roads. New concrete homes with traditional Tibetan decorations dot the stark brown countryside.

But the base government subsidy for building the new homes is usually $1,500 per household, far short of the total needed. Families have generally had to take out multiple times that amount in interest-free three-year loans from state banks as well as private loans from relatives or friends.

“Though the government assures that villagers have not borrowed beyond their means, many villagers around Lhasa have expressed pessimism about their ability to repay these loans, suggesting that the degree of debt for the new houses is beyond what they are comfortable with,” said Emily Yeh, a scholar at the University of Colorado at Boulder who has researched the program. “This should become clearer over the next few years as loans start to become due.”

In the model village of Gaba, right outside Lhasa, residents leased out their farmland for eight years to Han migrants to pay back the loans, which mostly ranged from $3,000 to $4,500. The migrants grow a wide variety of vegetables to be sold across China. Many of the Tibetan villagers now work in construction; they cannot compete with Han farmers because they generally know how to grow only barley.

“Renting out the farmland was suggested by the bank,” said Suolang Jiancan, the village head. “It would be a guaranteed income to pay back the loans.”

Among the Han, it is not just farmers who are profiting from the land. Large companies from other parts of China are finding ways to tap Tibet’s resources.

On July 19, China National Gold Group, the nation’s largest gold producer, began work at a polymetallic mine whose daily output is expected to reach 15,000 tons. Tibet has more than 3,000 proven mineral reserves, including China’s biggest chromium and copper deposits. China Daily, an official English-language newspaper, quoted a Tibetan official in March saying that mining could make up at least 30 percent of Tibet’s gross domestic product by 2020, up from 3 percent now.

A prominent mineral water company called 5100 that is registered in Hong Kong but managed from Beijing has set up a factory in Damxung, on a grassy plateau three hours north of Lhasa, to collect glacial runoff and bottle it as high-end mineral water. Last year, the company, named after the altitude of the glacier, produced almost two million gallons of water. The water is shipped out on the Qinghai-Tibet railway.

The water that is collected would otherwise flow through wetlands where yak graze. It is unclear how the factory’s work has affected the ecosystem. Jiang Xiaohong, the factory manager, who moved to Tibet three years ago, said the company did an environmental assessment before starting operations in 2006. “There’s no impact on the wetlands,” she said.

Because the company employs Tibetans, it receives government subsidies, Ms. Jiang said. About 95 percent of the 150 or so workers are Tibetan, and the average salary, including housing subsidies, is about $740 a month, a small fortune on the Tibetan plateau, she said. But ethnic Han are the company’s managers and owners, and the ones who ultimately profit from it.

Mr. Hao, the regional vice chairman, said the key to making Tibetans more competitive in business “is to enhance Tibetan people’s skills through education and training.”

The government has encouraged wealthier Chinese cities to finance school construction in Tibet. In the city of Shigatse, four hours from Lhasa, the Tibet-Shanghai Experimental School was completed in 2005 with an investment of $8.6 million from the Shanghai government. The principal, Huang Yongdong, arrived in January from Shanghai for a three-year posting. Nearly 1,500 students, all Tibetan, attend junior and senior high schools here.

A portrait of Mao hangs in the lobby. All classes are taught in Mandarin Chinese, except for Tibetan language classes. Critics of the government’s ethnic policies say the education system in Tibet is destroying Tibetans’ fluency in their own language, but officials insist that students need to master Chinese to be competitive. Some students accept that.

“My favorite class is Tibetan because we speak Tibetan at home,” said Gesang Danda, 13. “But our country’s mother tongue is Chinese, so we study in Chinese.”

On a blackboard in one classroom, someone had drawn in chalk a red flag with a hammer and sickle. Written next to it was a slogan in Chinese and Tibetan: “Without the Communist Party, there would be no new China, and certainly no new Tibet.”

Xiyun Yang and Helen Gao contributed research.

LHASA, Tibet — One warm morning on the campus of Tibet University, a couple of foreign journalists on a government-run tour of Tibet quietly broke away from the group to talk to students standing on a grassy lawn. Security guards dashed in and waved the students away.

Two days later, Chinese officials brought the 30 or so foreign reporters to the sprawling Tashilhunpo Monastery in Shigatse, the seat of power of the Panchen Lama, a reincarnated leader in Tibetan Buddhism. The officials had arranged for a monk to brief us on the monastery’s history. But reporters preferred to pepper him with questions about the selection of the 11th Panchen Lama — the Chinese government appointed one in 1995 after whisking off a 6-year-old boy endorsed as the genuine reincarnation by the exiled Dalai Lama. The boy and his family have not been seen since.

A foreign ministry official from Beijing quickly signaled an end to the talk. Later, walking through the white-walled monastery, the official shook his head and said to me: “The questions you all ask — what’s the word I’m looking for? — they’re ridiculous!”

These days, the Chinese government wants foreigners to think it is moving beyond Orwellian controls on information. In Beijing and most other parts of China, a foreign journalist can usually travel freely. Plainclothes officers don’t regularly follow journalists around. And ordinary people who talk to journalists usually do not fear reprisals from the authorities, unlike many Tibetans, who speak to foreign reporters only in quick, furtive conversations because of the omnipresent security forces.

China is pushing its state news agency, Xinhua, into new markets in hopes that foreign publications will run its stories as if they are those of The Associated Press or Reuters. Xinhua is even opening a newsroom in Times Square. One Xinhua reporter asked me, “When will foreigners view us like The A.P.?”

The Chinese government and its information agencies crave legitimacy among foreigners, and a growing number of Chinese journalists are trying to push the boundaries. But open and critical inquiry is still an alien concept to Chinese officials, as I discovered on this five-day government-run tour of Central Tibet.

In general, Chinese journalists still have to tip-toe around strict censorship measures. We foreigners know that we are being monitored, however subtly. And when it comes to certain important issues — like sovereignty and treatment of minorities — China places tight restrictions on domestic and foreign reporting.

That means that reporting on Tibet, Taiwan and Xinjiang, where ethnic tensions run high between Uighurs and Han, is still fraught.

Foreign journalists are forbidden from travelling independently to the Tibet Autonomous Region. A government-sponsored tour, held about once a year, is the only way in. And woe to reporters who cross some invisible line. Two Polish journalists recently discovered that they are on a blacklist for Chinese visas, one possibly because of his Tibet reporting.

Harmony, however, is the official catchword these days — including between the government and Tibetans, and the government and journalists. So two years after the largest Tibetan uprising in decades and the continued arrests of Tibetans accused of subverting state power, reporters on this trip received a heavy dose of ethnic entertainment, beautiful scenery and stage-managed interviews.

An hour after we checked into our hotel in Lhasa, as the afternoon sun dipped toward stark brown peaks, we were bussed to the Nangre Folk Customs Park for a buffet dinner that included several song-and-dance routines.

The next day, two tour buses and a police escort shuttled us around. At a village called Gaba, we talked to residents about new homes they had built with subsidies and loans under a government mandate called the “comfortable housing” program, begun in 2006. Gaba was a model village, and clearly not representative. In fact, the visit to Gaba was reminiscent of ones during the Cultural Revolution, when officials brought foreigners to similar model villages to demonstrate the country’s progress.

(The living room décor did not help: In each home, there was the same poster featuring the smiling countenances of Mao, Deng Xiaoping and Jiang Zemin, the three paramount leaders of China.)

There were occasional reminders of reality. One morning, our minders wrung their hands when cameramen on my bus filmed more than 150 military trucks with ethnic Han soldiers rumbling along a highway to Lhasa.

The last day, as we boarded the buses for a four-hour ride to the airport, reporters griped to one another about the tight leashes, but agreed that going on the trip was better than having no access at all. Just riding through the sweep of the Himalayas made up for all the frustrations. We stopped for lunch by a stunning holy lake, Yamdrok Tso, nestled high in the mountains.

Then, as we packed up to go, an Australian and a British reporter each stripped naked and dove into the waters.

I looked over at our minders. The ones from Lhasa were laughing, and so were our police escorts, from behind their mirrored sunglasses. It had been a long five days.