One had been held for almost a year without being charged or sentenced.
He is forced back as Chinese authorities reassert restrictions on images of the exiled spiritual leader.
They had sought the release of a popular religious leader jailed on disputed charges.
The detentions are part of a crackdown following a fiery protest in Sichuan province.
Leaflets called for Tibet's independence from China and for the long life of the Dalai Lama.
Chinese authorities close down a large Kalachakra religious ceremony in Gepasumdo county.
Images of the exiled spiritual leader are again confiscated by Chinese authorities.
A protest marcher disappears after nearing India's border with Tibet.
The attackers launch a lightning raid on a Tibetan village security post in Qinghai province.
His burning protest raises the total number of self-immolations to 121.
Chinese authorities are using homicide charges to crack down on deadly protest burnings.
Chinese authorities transfer him to a low-key job.
The number of casualties from the attack on the Dalai Lama's birthday-marking ceremony rises.
At least eight Tibetans are wounded in the shooting in Sichuan province.
An overseas rights group boycotts a global hotel chain over the project.
He is taken into custody after shouting slogans calling for independence for Tibet.
Six are freed without explanation before they serve their full terms.