COLOMBO (AFP) - Sri Lankans began voting on Monday in parliamentary elections in which former strongman Mahinda Rajapakse is hoping to become prime minister, eight months after losing the presidency.

Polling booths opened across the island, with voting set to continue for nine hours under tight security provided by 74,000 police and paramilitary forces, officials said.

Hundreds of voters had lined up outside some of the 12,300 polling booths across the country before they opened, officials said, adding that strict security was being enforced to ensure a free and fair election.

"Anyone who tries to impersonate genuine voters or create trouble at polling booths will be arrested," elections chief Mahinda Deshapriya told Sri Lankan television.

"Those who try to create trouble can have lunch at the police station and dinner in prison."

Police said they were also deploying nearly 3,000 patrols to protect polling booths as well as counting centres. Read more here.

Around 15 million men and women over the age of 18 years are eligible to vote in the election for a 225-member parliament.

Former president Rajapakse is standing in the north-western district of Kurunegala, but he was expected to vote in his home base of Hambantota in the island's south.