BEIJING A mob wielding stones and knives killed a police officer in a Tibetan part of Western China, state media said on Tuesday, a sign of ongoing unrest despite a massive influx of police and troops.
The latest news of unrest comes after protesters seeking to put pressure on China tried to disrupt the Beijing Olympic torch lighting ceremony in Greece.
In Tibet's capital Lhasa, meanwhile, 13 people were arrested for a monk-led protest on March 10, the first announcement of consequences for those involved in that largely peaceful march.
The march came on the anniversary of a failed 1959 uprising against Chinese Communist rule, days before rioting and looting that authorities say killed at least 19 people shook Lhasa.
China's assertion that protests have since faded after a massive influx of troops across Tibet and nearby areas was shaken when state media announced the death of the police officer in a fresh riot.
Wang Guochuan died in an attack on Monday on a group of police in the Ganzi (Garze) Tibetan Prefecture in Sichuan province, Xinhua news agency said.
Several other officers were wounded in the clash that ended when police opened fire.
"The police were forced to fire warning shots, and dispersed the lawless mobsters," the brief English report said. It did not say if the attackers were Tibetan or whether any protesters were hurt or killed.
But in a separate report, the Tibetan Centre for Human Rights and Democracy, an exiled group, said "at least one Tibetan protester was shot dead and another left in critical condition" after People's Armed Police fired on the crowd.
Some 200 protesters, including Buddhist monks and nuns, marched on the local township government chanting slogans for the Dalai Lama and for an independent Tibet, the group said. The protester shot dead was an 18-year-old monk, it said.
Foreign journalists have been prevented by officials from freely going to the area and Reuters could not independently verify the reports.
The Dalai Lama, Tibetan Buddhism's spiritual leader, has lived in exile in India since the 1959 uprising, and China accuses him of masterminding the wave of unrest across ethnic Tibetan parts of the country.
The 72-year-old Nobel Peace Prize winner denies the charge and his government-in-exile says 140 people have died.
But Chinese authorities are continuing a barrage of propaganda against him, accusing him of trying to sabotage the Olympics which open in Beijing on August 8 and which China had hoped would be a "coming-out party" for the rising power.
Instead, it is facing the prospect of worldwide protests as the Olympic torch circles the globe.
Protesters sought to disrupt the torch-lighting ceremony in Greece on Monday despite a tight police cordon, a moment that went unmentioned in the Chinese press.
In a report on the 13 arrests, the official Tibet Daily said the protesters had gathered in the afternoon of March 10 near Lhasa's Jokhang Temple, a central pilgrimage place in Tibetan Buddhism.
"On the square of the Jokhang Temple a number of monks appeared, yelling reactionary slogans and holding up a self-made 'snow-mountain lions' banner to gather a crowd and stir up trouble," the report said.
The "snow lion" banner is a widely used symbol of demands for Tibetan independence from China.
Police seized 15 protesters that day, and the Lhasa state prosecutor has since approved the arrest of 13, the report said. They were accused of an "illegal assembly".
Prosecutors said a key suspect, whose name was rendered in Chinese as "Luozhui", held aloft a snow lion banner earlier in the day and was "captured by police when preparing to shout reactionary slogans".
The report did not say how many of the suspects were Buddhist monks or lay people.
In response to the Lhasa unrest, China's Minister for Public Security, Meng Jianzhu, vowed stricter management of Tibetan Buddhist monasteries during an inspection visit to Lhasa, the Tibet Daily said.
"Tibetan Buddhist culture is an important constituent part of Chinese civilization," Meng said. "But any religion must act within the bounds of the constitution and the law, and not interfere in administration, the judiciary, education and so on."
(Additional reporting by Emma Graham-Harrison in Beijing and Krittivas Mukherjee in New Delhi; Editing by Lindsay Beck and Alex Richardson)