The awarding of Congress' highest civilian honor — personally bestowed on the exiled spiritual leader by President Bush on Wednesday — had already caused China to warn that Washington had "gravely undermined" relations.

The Ming Pao newspaper said hundreds of monks at the Zhaibung monastery in Lhasa had clashed with police.

It said that after the clash, the monastery was surrounded by 3,000 armed police who refused to allow more than 1,000 monks leave. It gave no other details and did not say if there were any injuries.

A call to the monastery was not answered Sunday.

Women who answered the phones at the Lhasa city government and police offices, who would not give their names, said they had not heard of any violence.

The Dalai Lama is lauded in much of the world as a figure of moral authority, but China reviles him as a Tibetan separatist.

The decision by Washington to honor the Dalai Lama is a setback to Beijing's efforts to lend legitimacy to its often harsh rule over Tibet and undermine support for the spiritual leader, who remains popular among Tibetans since fleeing into exile 48 years ago after a failed uprising.