Though two deaths were reported as anti-election protesters tried to disrupt Saturday's poll, which they reject as a sham, the interim Libyan government and the Western backers of last year's uprising hailed it as an early triumph for the new democracy.

No clear outcome is expected until today and questions remain about how the new 200-head national assembly will function, the importance of Islamic groups within it, and how growing demands for more autonomy in the east are to be addressed.

But the initial mood was one of jubilation as revellers lit the night sky over the capital, Tripoli, with fireworks.

"Allahu akbar (God is greatest), this is the freedom era - Sirte is free," chanted a local woman.

The election commission said after voting ended that 1.6million of about 2.8million registered voters had cast their ballots, a turnout of just under 60%.

"The first winner is the Libyan people," commission chairman Nuri al-Abbar said at a news conference late on Saturday, when repeatedly pressed for details of who had won.

In Washington, US President Barack Obama made clear that he saw the vote as vindication of his decision to back a Nato air assault which its critics denounced as the latest example of Western meddling.

"The United States is proud of the role that we played in supporting the Libyan revolution and protecting the Libyan people, and we look forward to working closely with the new Libya," he said.

Though the Libyan authorities boosted security to deal with threatened attacks by the former rebel militias which still wield power, it was ordinary Libyans armed with everything from clubs to automatic weapons who, in many cases, stood guard at polling stations.