Since the notice was issued Sunday by police in Gansu province's Gannan prefecture, two more local Tibetans, a herdsman and a farmer, died after setting themselves on fire near the Labrang Monastery in Gannan.

Dozens of ethnic Tibetans have set themselves on fire in China since March 2011 to protest what activists say is Beijing's heavy-handed rule in Tibetan regions, including parts of Gansu, Sichuan, and Qinghai provinces as well as Tibet itself. Many have called for the return of the Dalai Lama, their exiled spiritual leader.

Gannan police issued a notice saying that the string of recent immolations in the community had "seriously impacted social stability and harmony as well as people's ability to live and work.'' It said that in order to crack down on the demonstrations, people who tip off police about immolation plans will be rewarded 50,000 yuan ($7,700). The notice said that people who provide information on the "black hands'' who organized four recent self-immolations would be rewarded up to 200,000 yuan ($30,000).

The notice promised to keep the identity of informers confidential for their protection.

"Self-immolation is an extreme suicidal behavior that goes against humanity, society and the law and deprives people of their right to life,'' it said. "The instances of self-immolation that have occurred recently in our prefecture are part of a political conspiracy by the Dalai clique that means to split China and undermine national unity.''

Chinese authorities routinely deny Tibetan claims of repression and have accused supporters of the Dalai Lama of encouraging the self-immolations. The Dalai Lama and representatives of the self-declared Tibetan government-in-exile in India say they oppose all violence.

At least seven people have immolated in Gannan since March, including two women, and all have died, according to the Washington, D.C.-based International Campaign for Tibet.

A photo of the written notice was posted to Twitter on Thursday by the Beijing-based Tibetan writer Woeser.

A Gannan police officer who refused to give his name confirmed the details of the announcement. He said that no rewards have been paid out yet and no tips have been reported.

On Monday, a herdsman died in Gannan's Xiahe county near the Labrang Monastery after self-immolating. A day later, a farmer died after immolating on Xiahe's main street.