People started lining up even before the beginning of the polls, which opened across the country at 7:00 am. Voting will close at 4:00 pm.
"Two petrol bombs were hurled in Velvetthurai in Jaffna early in the morning," military spokesperson Udaya Nanayakkara told PTI. No one was injured in the blasts.
Large queues was seen in polling booths at Colombo and elsewhere in the country as people waited eagerly to cast their ballet.
President Mahinda Rajapaksa is pitted against former Army Chief General Sarath Fonseka in the sixth Presidential elections in the country.
Ahead of the Presidential polls, the Sri Lankan government vowed to protect democratic principles and assured free and fair polls. According to the Election Commissioner Dayananda Dissanayake, all measures are in place to ensure free and fair election.
Voters were turning up in large numbers at polling booths throughout the country. For the first time after the war concluded, election is being held island wide, including the Northern and the Eastern Provinces.
However, media reports said many Internally Displaced Persons (IDPs) have been stranded in Vavuniya without transport to take them to their respective polling divisions.
The opposition charged that it was done with a design to influence the outcome of the voting in that area, it said.
Themiya Hurulle with the New Democratic Front said the IDPS were deprived of the transport despite earlier assurances by the government that they will be provided with this facility on Tuesday.
The Marxist JVP member Vijitha Herath was detained in Vavuniya in the morning while he was on his way to Kilinochchi, the JVP media unit said.
He was detained together with former Presidential candidate Channa Gamage who is supporting General Sarath Fonseka.
In separate incidents armed groups had attempted to block voters from going to their respective booths at Horowpathana and Mulkirigala in North Central Sri Lanka but the matter was later solved with the arrival of the police.
Expressing relief after the first half of the voting got over, election monitors said barring minor incidents in Northern Jaffna and Western Gampaha the situation was more or less peaceful.
The Centre for Free and Fair Elections (CAFFE) said that there were more than 6 minor incidents reported early morning.
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