COLOMBO, May 16 (Xinhua) -- Sivanesathurai Chandrakanthan aliasPillayan, the leader of a former rebel group was sworn in as the chief minister for Sri Lanka's Eastern Province Friday evening, government officials said. Officials from the presidential secretariat said Pillayan took the oath of office before President Mahinda Rajapaksa in Colombo. Pillayan is the leader of the TMVP (Tamileelam Peoples Liberation Tigers), a military-political organization broke away from the main stream Liberation Tigers of Tamil Eelam in 2004. His appointment came after Rajapaksa's United People's Freedom Alliance (UPFA) won the Eastern Provincial election with the support of the TMVP on May 10.