BEIJING — Security has been stepped up in a Tibetan area in western China following several protests calling for a retrial for a revered monk jailed by Chinese authorities for independence activities.

Tibetans in Sichuan province's Yajiang county staged a hunger strike Saturday and Sunday, said a local police officer who refused to give his name. He wouldn't say how many people were involved or what they were protesting, adding Tuesday the hunger strike was already over.

The uptick in tensions occur in an area already tense since demonstrations against Chinese rule spread throughout Tibetan communities in March 2008. Ever since, large numbers of security forces have been garrisoned in the area, which has frequently been closed off to foreign journalists.

Armed police and troops have been stationed in front of many buildings in Yajiang since Saturday, said a woman at the Yajiang supermarket who only gave her surname, Yu.

Dozens of security forces patrolled the streets and checkpoints were set up to monitor people's comings and goings, Yu said, adding she was told by others that Tibetan monks and residents staged a protest in recent days.

The accounts corroborate details provided by a Beijing-based Tibetan who has friends living in Yajiang. The woman who did not want to be named said local residents told her 60 to 70 people were detained during the protests. Local police either denied or declined comment on any arrests.

The Beijing woman said the protesting Tibetans were calling for a retrial for Tenzin Deleg Rinpoche, a Tibetan monk who was sentenced to death in 2002 for involvement in bombings that killed one person and whose sentence has since been commuted to life in prison.

Tenzin Deleg gained a reputation as a champion of Tibetan culture and religion at a time when both seemed under threat from an influx of Chinese migrants into traditionally Tibetan western Sichuan.

Five members of Tenzin Deleg's family came to Beijing in recent weeks to deliver a petition seeking a new trial that was signed or marked with a fingerprint by 30,000 people but were forced to return to Sichuan, the woman said. They then went to the municipal courthouse in Sichuan's capital of Chengdu last week to request permission to visit the lama in prison but it was not immediately clear if the request was granted, she said.

Tibetan resentment against Chinese rule has been fueled by religious restrictions and competition for resources with migrants from the Han Chinese majority. The government says it has spent billions improving living conditions in minority areas and respects their rights.