Hundreds of Tibetan Buddhist monks celebrating the award of a US honour to the exiled Dalai Lama have clashed with Chinese police, resulting in an unknown number of injuries and arrests. Such violence has become unusual in recent years as China has tightened its grip on the region. The entry by police into Drepung monastery, on the outskirts of the Tibetan capital, Lhasa, was a sign of the hard line adopted against any sign of dissent. Dozens of monks had begun repainting with whitewash the exterior of a hall assigned as the residence of the Dalai Lama inside Drepung to show their joy after the US Congress awarded its highest civilian honour, personally bestowed by President Bush in Washington last week.