Tibetans in northwest China marked a tense traditional new year on Wednesday with prayer, the sounding of gongs and subdued defiance in the wake of a string of self-immolations and protests against Chinese control.

The traditional new year, or Losar, is a combination of Buddhist ceremony and family celebration observed across the Tibetan highlands.

But this year, unrest has overshadowed the celebrations and there has even been a call from an exiled Tibetan leader for people to shun festivities and instead pray for those who have suffered under Chinese rule.

At least 16 Tibetans are believed to have died after setting themselves on fire in protest since March, most of them Buddhist monks in Tibetan parts of Sichuan and Gansu provinces, next to what China calls the Tibet Autonomous Region.

This year's Losar has brought no major flare-ups.

But the heavy security in many areas and widespread Tibetan resentment of the government's presence remain a volatile combination that could be kindled by sensitive anniversaries and warmer weather.

China has ruled Tibet since 1950, when Communist troops marched in. It rejects criticism that it is eroding Tibetan culture and faith, saying its rule has ended serfdom and brought development to a backward region.

At the Kirti Monastery in Langmu, a town straddling Gansu and Sichuan, hundreds of red-robed Buddhist monks gathered to chant prayers while a large gong rang twice a minute.

Life is full of this pressure here. With the Dalai Lama in India and us here, it is very painful for us, said a 51-year-old Tibetan herder who had come to watch the ceremony. He gave his name as Jiata.

The Kirti monastery in Langmu is a smaller offshoot of a monastery in Sichuan that has been an epicentre of confrontation between the government and defiant Tibetans.

Authorities have blamed supporters of the Dalai Lama, the exiled Tibetan Buddhist leader, for fomenting defiance, but he remains a revered figure among most Tibetans.

The government controls everything we think. They say we have freedom to think as we like, but we don't, said the herder.

In Langmu, police and security forces stayed in the background. But some Tibetan areas have faced heavy police controls as authorities seek to deter fresh protests, especially ahead of March 10, the anniversary of the 1959 uprising against Chinese rule that ended with the Dalai Lama fleeing into exile.

Residents of the Tibetan capital, Lhasa, reached by telephone said security was tight.

There are many more policemen and police cars in the streets today, said one Lhasa businessman who asked not to be identified. You can feel the tension.

A LOT OF PRESSURE

Lobsang Sangay, prime minister of the Tibetan government-in-exile in northern India, this week urged Tibetans not to celebrate Losar this year, and instead to pray for those who have sacrificed and suffered under the repressive policies of the Chinese government.

His Holiness took part in the usual Losar religious prayers and rituals at the main temple, (but) this year the music and the singing were cancelled and were not a part of the celebrations, Tenzin Taklha, a senior aide to the Dalai Lama, told Reuters.

Chinese state media largely ignored mention of tension in their reports of the new year. But the official tibet.cn website said the celebrations were proof Tibetans had spurned the Dalai Lama's reactionary attempts to damage people's happy lives.

Labrang, a heavily Tibetan part of Gansu province, and home to a large monastery, was also calm and subdued.

This year celebrating new year won't be as good as last year. Why? You know why. The Communist Party is putting a lot of pressure on us Tibetans, said a Tibetan resident of Labrang, who declined to be identified.

But we have no plans to do anything different. There won't be any protests. Protest, and people get shot.

The Dalai Lama has blamed the self-immolations on cultural genocide by the Chinese, and has not directly called for them to stop. But he has long denied Chinese accusations that he incites violence and wants full-fledged independence.

Premier Wen Jiabao said last week the self-immolations were extreme acts to undermine stability in the region and had no popular support, the highest-level comments since increased tension in January.

For China, the self-immolations are a small, but potentially destabilising, challenge to policies toward minority groups and the region. The government has branded the immolators terrorists.

Anyone seeking to incite a small number of Tibetan region monks to take extreme measures and sabotage the stability of these regions ... will win no popular support, Foreign Ministry spokesman Hong Lei told a daily briefing.

Advocacy groups say as many as seven Tibetans were shot dead and dozens wounded during protests in January. China's official Xinhua news agency said police fired in self-defence on mobs that stormed police stations.

The official Tibet Daily said on Tuesday that a senior official had visited monasteries in Lhasa, calling on them to proactively guide monks to embrace the leadership of the Party and raise their sense of responsibility towards ethnic and national unity and social stability.

(Writing and additional reporting by Chris Buckley and Ben Blanchard in Beijing, and Abhishek Madhukar in Dharamsala; Editing by Nick Macfie)