Seventy suspected criminals have been arrested by police in Huangnan of Northwest China's Qinghai Province in connection with a string of self-immolations that have occurred since November 2012, a senior police officer said  on Thursday.

Lü Benqian, deputy chief of the Qinghai Provincial Public Security Department, said 12 of the suspects were arrested in connection with self-immolations that have occurred in the Huangnan Tibet Autonomous Prefecture.

Police will thoroughly investigate the cases and seriously punish those who incite innocent people to self-immolate, said Lü.

"Some of the victims were frustrated and pessimistic in life, and they wanted to earn respect through self-immolation," said Lü, who heads a special police taskforce investigating the self-immolations.

The self-immolation cases were influenced by the separatists of the Dalai Lama clique.

Phagpa, a young Tibetan in Dowa town of Tongren, attempted to incite a 24-year-old monk, Drolma Je, to self-immolate, but the monk's plan was discovered by his relatives and he was prevented from carrying it out, according to police.

In 2005, Phagpa illegally left China for India, where he received comprehensive training at an institute specially created for "Tibetan independence" forces of the Dalai Lama clique.

Drolma Je said he had known Phagpa prior to the latter's trip to India, meeting him in June and July last year. Phagpa told him that "self-immolation will be conducive to the return of the Dalai Lama to Tibet and a good thing for Tibetans."

After his return in July 2011, Phagpa worked as a teacher and organized free English training classes. In June 2012, he joined an illegal association in Tongren and delivered fiery speeches at the funerals of self-immolators on behalf of the organization.

Phagpa and Drolma Je have been detained and charged with murder and endangering public security.