The United Nations has sought an explanation from Sri Lanka on the death of three top Tamil Tiger leaders, after former army chief Sarath Fonseka alleged that surrendering Tamil rebels were killed in cold blood.

Sri Lanka will hold early presidential and general elections, the government said on Tuesday, hoping to cash in on the popular support it was enjoying after vanquishing the Tamil Tigers.

Tamil Nadu Government's decision to hold the 9th World Tamil Conference in Coimbatore next year is snowballing into a major political controversy, with AIADMK outrightly rejecting the move to hold such a meet and other opposition parties questioning its timing citing the plight of Tamils in Sri Lanka.

Voicing concern over the plight of the Tamils in Sri Lanka, DMK on Friday sought Centre's immediate intervention to ensure relief and rehabilitation to internally displaced Tamils in the island nation.

Sri Lanka on Sunday ordered a senior UN official to leave the country for his "propaganda in support of the Tigers" during the final phase of the 30-year-old civil war that ended in May.