A Chinese Communist Party agency says investigators have found that 15 officials in Tibet joined underground Tibetan independence organizations, provided intelligence to the Dalai Lama and his supporters or participated in activities harmful to China's security.

The publicizing of party officials supporting Tibetan separatism is highly unusual and suggests continuing unrest in the Himalayan region, which has prompted a heavy security presence since a wave of rioting and protests against Chinese rule in 2008.

A statement from the Communist Party Disciplinary Commission of Tibet, on its website, says that the wrongdoing was uncovered last year during an investigation and that the 15 officials received unspecified punishment.

The commission did not specify the groups that the party members joined, intelligence they provided or give any other details.