China says it has released more than a thousand people held for alleged involvement in anti-government riots in Tibet's capital, Llasa, three months ago.

The official Xinhua news agency Friday said authorities released 1,157 people who participated in deadly protests in March. It says 12 others were sentenced this week for their role in the protests.

In April, authorities handed down punishments to 30 people on charges including arson, robbery and attack on state organs during the unrest.

The news agency quotes Tibet's vice chairman Palma Trily as saying another 116 people remain in custody awaiting trial.

The report was published two days after human rights group Amnesty International urged China to reveal what happened to more than a thousand people arrested during the government crackdown on protesters.

Some information for this report was provided by AFP, AP.