Tibeten monks have disrupted a tour of Lhasa by foreign journalists.
The journalists were the first to be allowed back to Tibet since protests erupted two weeks ago.
About 30 monks shouted pro-Tibetan slogans and defended the Dalai Lama as journalists toured the Jokhang Temple, the visiting reporters said.
China has accused the Dalai Lama of masterminding the protests, but the US has urged Beijing to begin dialogue with Tibet's exiled spiritual leader.
Foreign journalists were expelled from Tibet at the height of the unrest, but on Wednesday China allowed a group of about two dozen reporters into Lhasa for a three-day escorted visit.
The BBC's request to be included in the group was turned down.
The monks' protest came as they toured the Jokhang Temple - one of Tibet's holiest shrines.
One monk shouted "Tibet is not free, Tibet is not free" before he started to cry, an AP journalist at the scene, Charles Hutzler, reported.
Another monk said the rioting on 14 March "had nothing to do with the Dalai Lama".
The monks said they had not been allowed to leave the temple since the rioting.
China has increased its security presence in Lhasa since the unrest
Government handlers told the journalists to leave and tried to pull them away, the reporter said.
Later, the area around the Jokhang Temple was sealed off by riot police.
The protests began on 10 March and developed into violent rioting in Lhasa before spreading to neighbouring regions.
China says 19 people were killed by rioters. The Tibetan government-in-exile says about 140 people have been killed in a crackdown by Chinese security forces.
The group of journalists has also visited a medical clinic and a clothing store, where Chinese authorities say five girls were trapped and burned to death, AP's reporter added.
A reporter for the London-based Financial Times, meanwhile, said that the Tibetan quarter of the city resembled a war zone, with burnt-out buildings, shuttered businesses and groups of soldiers on every corner.
"The smell of burning buildings still hangs in the air nearly two weeks after violent rioting swept through the old Tibetan quarter of Lhasa," the Financial Times's Geoff Dyer reported.
The rioting appeared to have been more prolonged and destructive than previously thought, he wrote.
Charles Hutzler described to the BBC a city divided.
"In sort of the more recently built up, very Chinese part of Lhasa, life seems to be going on fairly normally," he said.
The journalists will spend three days in Lhasa
"But in the older, Tibetan section of the town and the blocks leading to it we could see the remains of burnt-out buildings."
The reporters said there was a heavy security presence in the Tibetan quarter, with squads of police and soldiers on every corner.
But in the new town, they described life as returning to a semblance of normality, with shops and restaurants busy with customers.
On Wednesday, US President George Bush had "encouraged the Chinese government to engage in substantive dialogue with the Dalai Lama's representatives," White House spokeswoman Dana Perino said.
But the fact that it has taken Mr Bush this long to talk directly to Mr Hu shows that the US is treading carefully in its response, says the BBC's Jonathan Beale in Washington.
Despite calls from rights groups for an Olympic boycott, the White House has already made it clear that Mr Bush will still attend the opening ceremony of the Beijing Games.