Thousands of voters queued outside polling stations on Monday as voting for Bangladesh's landmark Parliamentary election started amid unprecedented security, with army troops and other paramilitary forces keeping a sharp vigil.

The voting started at 8.00 am and it is to continue until four in the evening while the counting will begin, manually, immediately at the end of voting in 35,263 polling stations across the country.

The Election Commission officials said they expected the unofficial results to be announced by early Tuesday in the ninth Parliamentary election in which former Premier Sheikh Hasina's Awami League-led Grand Alliance and her arch rival Khaleda Zia's BNP-led four party coalition appeared as the major contenders to form the next government.

Over 8.10 crore voters were enrolled in the country's first-ever digital electoral roll as the election to the 300-seat Parliament comes after a seven-year gap at the end of two years of the state of emergency under an interim government, crucially backed by the army.

No major pre-poll violence was reported as electioneering ended on Friday midnight but officials and reports said a number of people were arrested as rival candidates at several places tried to distribute money in city slums and in remote villages in their bid to 'buy votes'.

Police said they seized cartons filled with Taka 41.5 lakh in the south eastern port city of Chittagong in one such case, while they arrested several activists mostly belonging to the BNP-led alliance with cash allegedly to be used to woo voters.

Supporters of rival candidates also kept a sharp vigil in slum areas and particular pockets for thwarting such 'vote buying' bids.

The government earlier deployed some six lakh security personnel, including nearly 50,000 army troops to ensure the holding of a free and peaceful election.

Bangladesh's interim government chief had on Sunday vowed to ensure a 'free and fair' election as he asked his countrymen to 'act responsibly' while casting votes in the parliamentary polls to restore democracy in the Islamic nation.

A total of 1,552 candidates are contesting the polls and more than 81 million people -- 33 per cent of them first-time voters -- are eligible to cast their ballots.