Many had previously been authorized by China to travel, but may now not leave the country.
Authorities ignore repeated appeals for help from Tibetan residents, sources say.
He is released after authorities find no evidence that he circulated photos of a December protest challenging Chinese rule.
Authorities had blocked their participation in the Kalachakra teachings given in India by the Dalai Lama.
Work expected to resume in April will now begin again in February, a local source says.
Emphasis on Mandarin Chinese in Sichuan's provincial capital forces children back to their villages if they want to study Tibetan.
Work will resume in the spring, though, with the pace of destruction more 'aggressive,' a local source says.
Tibetan residents of western Chinese provinces pray, share teachings in spite of official threats.
Many fast or pray in private gatherings to avoid scrutiny by the police.
Tibetans living in China are warned not to spread news of the event online or organize gatherings in support.
Many were told by Chinese officials their families would be harmed if they failed to return home.
Villagers attempting to stop the assault were also attacked, local sources say.