Beijing, May 22 (IANS): A Tibetan education activist was on Tuesday sentenced to five years in prison by a Chinese court for inciting separatism, Amnesty International (AI) said, calling the sentence "unjust" and urging his immediate release.

The main evidence against Tashi Wangchuk, who was sentenced by a court in Yushu Tibetan Autonomous Prefecture in Qinghai province, was a 2015 video by the New York Times about his campaign for saving the Tibetan language, according to his lawyer.

"Today's verdict against Tashi Wangchuk is a gross injustice. He is being cruelly punished for peacefully drawing attention to the systematic erosion of Tibetan culture," AI East Asia Research Director Joshua Rosenzweig was cited as saying by Efe news.

Before his arrest, the 31-year-old activist had expressed concern over the fact that many Tibetan children could not fluently speak their native language, contributing to the progressive extinction of the Tibetan culture.

"Tashi must be immediately and unconditionally released," demanded AI, pointing out that the activist had already spent two years in detention without access to his family.

Rosenzweig claimed that Tashi Wangchuk "was a human rights defender and prisoner of conscience who used the media and China's own legal system in his struggle to preserve Tibetan language, culture and identity".

In the New York Times video, the activist had highlighted "the extreme discrimination and restrictions on freedom of expression that Tibetans face in China today".

Non-profit Human Rights Watch (HRW) also criticized the prison term for Tashi Wangchuk, whose "only crime was to peacefully call for the right of minority peoples to use their own language", a right safeguarded by the Chinese Constitution.

"His conviction on bogus separatism charges show that critics of government policy on minorities have no legal protections," said HRW China Director Sophie Richardson.