A prominent Tibetan political prisoner has been freed by China's government, in a gesture expected to improve the atmosphere for next week's summit between the Chinese and American presidents. The Tibetan Buddhist nun was jailed for banned political activities, including singing.

Human rights activist John Kamm says Tibetan Buddhist nun Ngawang Sangrol has been released on parole nine years early. She had been in prison in Lhasa, Tibet for the past decade.

The warden of her prison says she was serving time for "counter-revolutionary propaganda and incitement." Activists say she was jailed for pro-independence protests, and for recording songs that were smuggled out of the prison, embarrassing the Chinese government.

Beijing has released other political prisoners on the eve of high-profile meetings, reaping some good will in the process. Mr. Kamm said this release is timed to coincide with the summit in Texas next week between President Bush and Chinese President Jiang Zemin. "I'm sure that this release has had a very positive impact. All of my friends in Washington, in the House, the Senate, are just delighted by it," he said. "We are hoping to see many more releases."

The nun's case is one of 18 the U.S. State Department raised with China a year ago, in a human rights dialogue, and activists say about half of those have been released this year.

China imposed communist rule on Tibet after its troops took control of the huge mountainous area in 1950. Tibet's leader, the Dalai Lama, fled into exile in India after a failed 1959 uprising against Chinese rule. Many Tibetans, particularly such religious figures as nuns and monks, remain strongly loyal to the Dalai Lama, and stage protests from time to time.