A Tibetan author jailed by China for writing a book about the Himalayan region has been released after a decade in prison, a US-based rights group said. Dolma Kyab, 39, was freed last week after he was convicted a decade ago of “endangering state security”, the International Campaign for Tibet said. READ MORE: China ‘restricts passports’ for Tibetans, Uygurs, says rights group Kyab’s trial happened in secret in Tibet’s capital Lhasa and only came to light after a letter he wrote while incarcerated was smuggled out of prison months after his 2005 sentencing. According to a copy of the letter seen by the rights group at the time, Kyab said he was imprisoned because of the ideas he expressed in his unpublished book The Restless Himalayas . He added that the authorities believed his writing was connected to Tibetan independence. In his book, Kyab wrote about conceptions of Tibetan identity as well as Tibetan hopes for exiled spiritual leader the Dalai Lama to return to his homeland, the rights group said. “We live in a time of national devastation. We have weathered countless years of darkness, countless dark nights,” he wrote. He also discussed the “political burden” suffered by Tibetans because China’s Han majority “impose their way of thinking onto Tibetans”, thus “destroying the concept the Tibetans have of themselves”. China has been accused of trying to eradicate its Buddhist-based culture through political and religious repression and large-scale immigration by Han Chinese. Beijing says that Tibetans enjoy extensive freedoms and that it has brought economic growth to the region. READ MORE: China stresses social stability over economy in Tibet 50th anniversary address Tibetan spiritual leader the Dalai Lama fled Tibet after an abortive uprising in 1959 and established a government-in-exile in Dharamsala in India. After his release from the Qushui Prison in Lhasa, Kyab was taken back to his hometown, where family and friends draped him with white blessing scarves, the International Campaign for Tibet said.