The militant group's chief of international relations announced Sunday that the war had reached its "bitter end."
"We remain with one last choice – to remove the last weak excuse of the enemy for killing our people," wrote Selvarasa Pathmanathan in the statement. "We have decided to silence our guns. Our only regrets are for the lives lost and that we could not hold out for longer."
The Tigers, formally known as the Liberation Tigers of Tamil Eelam (LTTE) have been fighting for an independent Tamil state in northern Sri Lanka since 1983. They complain of discrimination and ill treatment at the hands of the island's Buddhist Sinhalese majority.
Mr. Rajapakse was greeted on his return home by supporters waving flags and setting off firecrackers.
According to The Times of London, on Sunday night, the Sri Lankan military killed 70 of the remaining fighters from the Tigers who were holding tens of thousands of civilian hostages in a shrinking patch of jungle territory.
The government claims to have freed all hostages, which AFP reports number between 20,000 and 50,000.