Tibetan monks disrupted an official news briefing at a temple in the capital Lhasa today, it was reported.
The monks shouted that Chinese authorities were lying about unrest in the Himalayan region, foreign reporters said.
The incident was an embarrassment to the Chinese government, which brought a group of foreign reporters to Lhasa for a stage-managed tour of the city, where authorities say stability has been restored since violence broke out on March 14th.
The government has claimed security forces acted with restraint in the face of the unrest.
A group of uninvited young monks at the Jokhang Temple, one of the most sacred in Tibet and a top tourist stop in central Lhasa, stormed into a briefing by a temple administrator.
Hong Kong's TVB aired television footage of the outburst in front of the first foreign journalists allowed into Tibet since the violence, showing around 30 monks in crimson robes, some weeping, crowded around cameras.
The monks said they had been unable to leave the temple since March 10th, when demonstrations began in Lhasa on the 49th anniversary of an abortive uprising against Chinese rule that saw Tibet's spiritual leader, the Dalai Lama, flee to exile in India.
So far, China says 19 people have been killed by rioters incited by Tibetan separatists, while the Tibetan government-in-exile says 140 people have been killed in the crackdown on protesters by Chinese security forces.
"They just don't believe us. They think we will come out and cause havoc - smash, destroy, rob, burn. We didn't do anything like that - they're falsely accusing us," said one monk.
Officials in charge of the media delegation did not confiscate notes or film from reporters but told them to move on.
US President George W. Bush spoke to Chinese President Hu Jintao yesterday and urged him to talk with the Dalai Lama, Tibet's exiled spiritual leader. In a telephone conversation, Mr Bush also urged restraint in China's response to protests in Tibet.
In response, Mr Hu said the Dalai Lama must renounce support for independence of Tibet and Taiwan and stop encouraging violence and illegal activities aimed at harming the Olympics.
The Dalai Lama denies he wants anything more than greater autonomy for his homeland and has criticised the violent protests. But he said today the Olympics were a chance for the world to remind China of its human rights record.