The statement by the publicity department of the Communist Party’s Sichuan Committee followed clashes since last week between ethnic Tibetans and authorities in the mountainous frontiers of Sichuan that border Tibet proper.

Security forces have clamped down on the area, setting up road blocks and cutting off some communications, making it impossible for journalists and others to independently verify conflicting accounts.

“Evidence shows that the violent attacks in Ganzi Tibetan autonomous prefecture were long plotted by separatist forces,” the information office of the Sichuan government said, according to the China Daily newspaper.

The incidents were “plotted copycats” of the deadly riots that engulfed Tibetan areas in 2008, “with a deliberate plan to incite hatred among the people,” according to Sichuan authorities cited by the Global Times, a popular tabloid owned by the People’s Daily, the Communist Party mouthpiece.

Calls to the Sichuan government were unanswered on Wednesday.

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

Tibetan advocacy groups say as many as seven Tibetans have been shot dead and dozens wounded when protests in the region were quelled by police and security forces, but China’s official Xinhua news agency reported that police fired in self-defense on “mobs” that stormed police stations.

The “separatists threatened the housing and personal safety of local Tibetans so they would not celebrate the Lunar New Year in China,” the China Daily said.

It said the Tibetans had “spread rumors that three monks would set themselves on fire” in Luhuo township, where Tibetan rights groups say two Tibetans were shot dead by police last Monday.

“The separatists incited the crowd by shouting slogans and putting up banners at the busiest part of the counties demanding they join their protests, which soon turned violent,” said the China Daily.

Qi Zhala, the top Communist Party official in Lhasa, the capital of the Tibet Autonomous Region, urged security forces to increase their surveillance of monasteries and along major roads, the Lhasa Evening Daily said on Monday.

US Special Coordinator for Tibetan Issues Maria Otero said in a statement after the first two shootings last week that the United States was “gravely concerned” about the reports of violence, underscoring the potential international ructions that could follow from continued unrest in Tibetan areas.

Over the past year, there have been at least 16 incidents of Tibetans setting themselves on fire in response to Beijing’s grip over Tibetan affairs.