BEIJING — A young Tibetan monk set himself on fire Monday in a remote western town to protest Chinese policies, the fourth monk from Kirti Monastery to self-immolate this year, according to a Tibet advocacy group based in London.

The group, Free Tibet, said in a news release that the monk, Kalsang, set himself ablaze at 2 p.m. in a vegetable market in the town of Aba, known in Tibetan as Ngaba. Kalsang was holding a picture of the Dalai Lama, Tibet’s exiled religious leader, at the time and called for religious freedom, the group said. Security officers extinguished the flames. the group said, but the monk’s condition was unclear.

Free Tibet did not specify the sources of its information. There was no immediate comment from Chinese officials, and no mention of the self-immolation in China’s state-run press.

The first self-immolation this year at Kirti, a monastery that was at the heart of local protests against the authorities in 2008, occurred on March 16, when Phuntsog, a 20-year-old monk, killed himself. On Sept. 26, two other young monks at Kirti set themselves on fire, but were believed at the time to have survived. One of the two monks, Lobsang Kalsang, was a brother of Phuntsog.