Widespread international concern was voiced over the number of civilians killed during the fighting, while aid groups now fear for the welfare of 300,000 Tamils held in the state-run camps.
The Tigers' new leader, Selvarasa Pathmanathan, was detained in Malaysia on Wednesday and flown to Sri Lanka for questioning by the government.
Pathmanathan, who was based outside the country, had been attempting to rebuild the movement from overseas after its founding chief Velupillai Prabhakaran was killed in the final stages of fighting in May.
The Tamil National Alliance, a front for the Liberation Tigers of Tamil Eelam (LTTE), took five seats on the Vavuniya municipal council, while President Mahinda Rajapakse's People's Alliance got only two.
However the president's party won 13 seats on the Jaffna municipal council, defeating the Tamil National Alliance, which took eight.
Saturday's elections -- the first in the area since government troops finally quashed the LTTE in May -- were seen a