BEIJING (AFP) - Chinese state security officials have arrested a popular Tibetan singer and a composer, apparently because of the implicit political content of their music, an official said.

The singer and composer, known as Namkha and Bakocha respectively, were taken into custody around March 10 in Tongde county, a traditionally Tibetan area now part of northwest China's Qinghai province, a police officer and the US-based Radio Free Asia (RFA) said.

"It was the state security police who arrested them," said a Tibetan police officer in Tongde county's public security bureau.

"I don't know what charges were filed against them, but it was because of political reasons," said the officer, who identified himself as Wu Jianchu. The two men sang folk songs and were popular in the area and famous throughout the province, Wu told AFP.

The arrests appear to have been prompted by the mildly political content of Namkha's songs, RFA sources said. The songs in question are titled "Tsenpoe Poinya," or "King's Messenger," and "Amdo Pogoe," meaning "Courageous Amdo Man."

Chinese state security officials in Qinghai's Hainan prefecture are confiscating all CDs made by the men.

"All their CDs have been confiscated by the police," Wu said. Both men come from a nomadic area in Qinghai. Bakocha is a monk at the Ba Shangtse Monastery in Tongde county. Local security officials went to the monastery and instructed the monks to surrender those CDs, RFA said. They warned the monks that they would face "serious consequences" if they were found to possess Namkha's music, the source said.