Colombo, Aug 17 (IANS): Sri Lankan voters on Monday queued up to cast their votes for a parliamentary election amidst tight security to elect a new government.

Around 15 million people are expected to cast their votes in the island nation in over 12,000 polling centres, reported Xinhua news agency.

Voting commenced at 7 a.m. and will end at 4 p.m.

An estimated 75,000 police officers and special task forces have been deployed across the country to maintain law and order along with over 50 foreign observers being present at polling booths.

The parliamentary elections was announced by President Maithripala Sirisena in June after he dissolved parliament just six months after being elected to power.

A close battle between the United National Front (UNF) coalition and the opposition United People's Freedom Alliance (UPFA) will be seen in the elections.

The UNF is led by Prime Minister Ranil Wickremesinghe while the UPFA has former president Mahinda Rajapakse contesting as its main candidate from the province of Kurunegala.

Rajapakse is looking at making a political comeback and eyeing to be the nation's new prime minister if the opposition wins majority in the polls.

The department of elections said voting results are expected to be announced on Tuesday.