Ballot-counting was under way Sunday in Sierra Leone's first presidential election since United Nations peacekeepers withdrew two years ago.

Many people in Sierra Leone see the poll as a chance to show that they have finally emerged from a legacy of coups and a decade-long, diamond-fuelled war as a multiparty state that can transfer power peacefully.

Seven candidates are vying to succeed President Ahmed Tejan Kabbah. Term limits prevent the 75-year-old leader from running for a third five-year term.

The head of Sierra Leone's electoral commission said voting finished on time and without incident Saturday at most polling centres, despite rain and long lines.

Late Saturday, police used tear gas to disperse crowds of youths setting up makeshift roadblocks in a part of eastern Freetown. It was unclear what sparked the incident or whether it was related to the polling.

A small number of violent incidents were reported in western Freetown, and polling was delayed in one southern town because of lost ballot boxes.

Results from Saturday's presidential and parliamentary poll will be released progressively, with final tallies within 12 days of voting.

Saturday's victor must take more than 55 per cent of the vote to avoid a run-off between the top two finishers.

In other races, some 572 contenders vied for 112 parliamentary seats. About 2.6 million of the nation's five million people are registered to vote.

The hope is that a peaceful vote will pave the way for development in a country where diamond wealth is difficult to see in fetid slums and dilapidated roads.