Shahrour said the group shouted that Chinese authorities have arrested about 1,000 monks.
It is unclear what happened to the monks after their extraordinary outburst.
The incident staged outside Lhasa's Jokhang temple on Thursday is embarrassing for China's government, which brought the foreign media delegation to Tibet to show that life has returned to normal in the Himalayan region after widespread unrest.
The Jokhang temple, regarded as one of the most sacred sites for Tibetan Buddhists, is located in the heart of the old quarter of the city.
The quarter was the scene of some of the worst violence during a day of rioting on March 14, which followed four days of protests to mark the anniversary of a failed 1959 uprising against Chinese rule.
China generally does not permit foreign journalists to enter Tibet.
A number of world leaders have been calling on China to moderate its ongoing crackdown of Tibetan unrest.
George Bush, the US president, encouraged Hu Jintao, his Chinese counterpart, on Wednesday to open talks with the Dalai Lama, Tibet's exiled spiritual leader.
Hu said that the Dalai Lama must renounce support for the independence of Tibet and stop encouraging violence and illegal activities aimed at harming the Olympics, according to a Chinese foreign ministry statement.
The Dalai Lama denies he wants anything more than greater autonomy for his homeland and has criticised the violent protests.
But he said on Thursday the Beijing Olympics in August provided a chance for the world to remind China of its human rights record.
"In order to be a good host to the Olympic Games, China must improve its record in the field of human rights and religious freedom," the Dalai Lama told India's NDTV news channel in an interview to be aired on Friday.
"It's very logical, very reasonable."
Meanwhile, the Belgian government has indicated it may boycott the Olympic Games over China's crackdown in Tibet.
Didier Reynders, the Belgian vice premier, told Le Soir newspaper on Wednesday that staying away from China "is not an option that we reserve today. But we can never exclude the worst."
His comments came a day after Nicolas Sarkozy, France's president, suggested he could boycott the opening ceremony of the Olympics in August.
The demonstrations in Lhasa have spread to parts of Chinese provinces that border Tibet and have large ethnic Tibetan populations.
|South Korean activists denounce China on |
Thursday over its crackdown [GALLO/GETTY]
China says 19 people were killed at the hands of Tibetan mobs. The Tibetan government-in-exile says 140 died in Lhasa and elsewhere - most of them Tibetan victims of security forces.
China has defended its crackdown on the Tibetan protesters as a necessary move to contain violent mobs, while pouring troops into the region.
Human Rights Watch said the United Nations human rights council should
address the crisis in Tibet.
Human Rights Watch said Australia, the European Union, Switzerland and the US raised human rights abuses in Tibet during a recent session of the UN Human Rights Council, but China blocked debate, backed by Algeria, Cuba, Pakistan, Sri Lanka and Zimbabwe.