China suffered a propaganda own goal today when a state-organised media trip to Lhasa was interrupted by protesting monks who accused the government of lying to the outside world.

More than 30 monks at Jokhang Temple - the most sacred in Tibetan Buddhism - burst in on a briefing during the first foreign journalists tour since riots erupted in the Tibetan capital on March 14.

Interrupting a speech about inter-ethnic harmony by the head of the temple's administrative office, the lamas surrounded the journalists and said, "They are tricking you. Don't believe them. They are lying to you."

"They want us to crush the Dalai Lama and that is not right," one monk told the Associated Press news agency, denying that Tibet's exiled spiritual leader was responsible for the unrest.

The monks, who first spoke Tibetan and then switched to Mandarin so the reporters could understand them, said they were willing to risk arrest to speak out.

"It was an astonishing act of defiance," said Callum MacLeod of USA Today. "The monks hijacked the briefing. They were desperate to get their story out - that they have no freedom, that 120 of them haven't been allowed to leave their dormitories since March 14."

Another reporter on the trip, Wang Che-nan, a cameraman for Taiwan's ETTV, told Reuters that the incident lasted about 15 minutes, after which unarmed police took the Tibetans to another area of the temple.

China's state-run Xinhua news agency noted that the media tour had been briefly disrupted by monks.

The incident will be an embarrassment to the government, which organised the trip to show that stability had returned to Lhasa and to emphasise the murderous behaviour of some Tibetan rioters.

The reporters have one full day in the city, where they will meet officials and victims of the arson attacks, beatings and other ethnic hate crimes.

According to the authorities, at least 22 people died in Lhasa, most of them Han and Hui Chinese who either burned to death in fires or were killed by members of the indigenous population.

Overseas Tibetan groups say almost 140 people died, many of them shot by the security forces in Lhasa and other areas of unrest in Qinghai, Gansu and Sichuan provinces.

It is impossible to confirm or disprove either figure because of tight media restrictions on the affected areas.

Chinese officials and many bloggers have criticised foreign media organisations for "misrepresenting" the riots as protests, for calling the police response a "crackdown", for underplaying the ethnic violence, and for wrongly captioning pictures to cast the security forces in a bad light.

Public anger has manifested itself in online denunciations, hate mail and death threats to some organisations. CNN briefly moved out of its office.

The Sunday Times was criticised in the state-run media for a comment article written by Michael Portillo that compared the Chinese communist party's use of the Beijing Olympics this year to the German Nazi's use of the Berlin Games in 1936.