Sri Lanka's [Images] Marxist-backed Prime Minister Mahinda Rajapakse Friday won the closely-fought presidency with a narrow 50.33% of the popular vote, official results showed.

• Bomb attack on mosque

Rajapakse, who turns 60 Friday, received 4.88 million votes, beating his nearest rival, right-wing Ranil Wickremesinghe, on 4,880,950 votes, the final result released by the election commissioner indicated.

Election Chief Dayananda Dissanayake said the result would be conveyed to all 13 candidates at a formal meeting in Colombo at 1300 IST.

When the final result is officially declared, the outgoing President Chandrika Kumaratunga's second and final term comes to an end, but she can remain in office until Rajapakse assumes office within two weeks.

Violence, meanwhile, continued to plague the country's east, with unidentified attackers lobbing grenades into a mosque early Friday, killing four men at prayer and wounding at least 25 others, police said.

The grenade blasts ripped through the mosque at the town of Akkaraipattu in the district of Ampara, 350 km east of the capital Colombo by road, while hundreds of devotees were praying, a police spokesman said.