Chinese police have confirmed that a bomb blast has damaged a government office in a majority Tibetan region of southwest China.
The explosion just after midnight Monday shattered windows at the station in Bogexi, a town in the predominantly Tibetan Ganzi prefecture, said Liu Xiaojun, a police official.
The building was not yet occupied and an investigation was under way, said Liu, who works at the public security bureau in Batang county, which oversees the town. Batang, in Sichuan province's far west, is about five miles from the Tibetan border.
Chinese state media blamed the attack on "terrorists." China has tightened security in Tibet and neighboring Tibetan regions to try to prevent Tibetans from marking this month's anniversary of a failed 1959 uprising against Chinese rule.
Tibetan rights groups have reported several small anti-China protests in Tibet and nearby areas in recent days.
The U.S.-based group International Campaign for Tibet says Chinese authorities in Qinghai province detained 100 Tibetan monks who held a peaceful protest last month.
It says the monks were taken from a Buddhist monastery in Qinghai's Mangra county last week and ordered to undergo political re-education at an undisclosed location.
The International Campaign for Tibet also accused Chinese authorities of beating and torturing some monks who remained at the monastery.
It attributed the information to a Tibetan exile whose name it did not disclose and who the group says has connections in Qinghai.
Most reports of scattered Tibetan protests cannot be confirmed independently because Chinese authorities have barred foreign journalists and visitors from Tibetan areas.