Reports from Tibet say Chinese security forces have launched a wave of detentions in Lhasa following two self-immolations there on Sunday.
Witnesses to the immolations had been arrested and Tibetans from outside Lhasa sent home, the reports said.
The two Tibetan men set themselves on fire outside the Jokhang temple in an apparent anti-China protest.
There have been several such incidents in Tibetan areas outside Tibet but these were the first in Lhasa.
One of the men died while the other “survived with injuries”, Xinhua news agency said. Both were reportedly Tibetans from outside Tibet.
Meanwhile a Tibetan mother of three has died after setting herself on fire in Sichuan province, reports say.
The woman, in her 30s, set herself on fire outside a monastery in Aba county, an ethnically Tibetan area where many of the self-immolations have taken place.