Colombo, Jan 08 (ANI): Voting began on Thursday throughout Sri Lanka in a presidential election where incumbent President Mahinda Rajapaksa is facing an unexpected challenge to his rule from his former Health minister Maithripala Sirisena. Police said no incidents have been reported from any parts of the country so far.The army is on alert to provide support if needed. Election monitors have reported less violence than in earlier elections in the run up to the polling day. Voters were also keen to see the poll pass off peacefully. Rajapaksa won around 58 percent of the vote in the last election, surfing a wave of popularity that sprang from the 2009 defeat of Tamil Tiger separatists who had waged a crippling war against the government for 26 years. Although his popularity has waned, Rajapaksa called the election two years early, confident that the perennially fractured opposition would fail to find a credible challenger.