Nearly 18.8 million Algerians were registered to cast ballots at more than 42,000 polling stations for the 389-seat National People's Assembly, with 28 parties and 12,229 candidates in the running.

The day after two homemade bombs killed a police officer and injured five other people - 48 hours after Al Qaeda had called on Algerians to boycott the poll - no incidents had been reported by midday (1200 GMT).

But turnout was light at voting stations.

"There's only old folks voting," grumbled a poll observer from Algeria's dominant political party, the National Liberation Front (FLN), in the Bab-El-Oued district of Algiers. "It's a war veterans' vote."

"This is in order to get an apartment," said a veiled Amina Abdoune, 24, who lives in a one-room flat with her parents and siblings, as she deposited her ballot at a school, hopeful that the government will ease an acute housing shortage.

First results were due late Thursday night, and the outcome was not expected to significantly change the political landscape in Algeria, with allies of President Abdelaziz Bouteflika, 70, expected to retain a majority of seats.

The voting was nevertheless being closely monitored by the United States and Europe, which regard oil- and gas-rich Algeria as a strategic partner in the broad fight against Islamist extremism.

On the eve of the vote, a police officer was killed and five other people injured by two homemade bombs in Algeria's third-biggest city Constantine.

It was the most serious incident in an Algerian city since triple suicide bombings April 11 in the capital Algiers, claimed by Al Qaeda, took 30 lives and left 220 injured.

Interior minister Yazid Zaerhouni condemned Wednesday's blasts as "an act of sabotage against the Algerian democratic system," and urged Algerians to go to the polls in big numbers "to show their attachment to democracy."

"The best way to respond to such attacks is a strong turnout for the parliamentary elections," he said on public radio.

Bouteflika, elected in 1999, is credited with ending nearly a decade of violence - triggered with the abrupt cancelation of elections in 1992 that an Islamist party was poised to win - that cost an estimated 150,000 lives.

The president cast his ballot Thursday at a school in the verdant hills high above Algiers, accompanied by a bewildered-looking young nephew, bodyguards in dark glasses, and live television news cameras.

Political analysts say that, with power in Algeria concentrated in the president, whose mandate ends in 2009, many Algerians have little interest in parliament and may therefore not bother to vote.

Heightened security has been put in place throughout Algeria, North Africa's biggest country, and the interior ministry has ordered trucks to stay off the roads, markets to be closed, and sporting and cultural events to be postponed to another day.

Thursday was declared a public holiday to encourage citizens to vote.

Since the April 11 bombings, security forces have redoubled their campaign against stubborn pockets of Islamist extremists in remote parts of the country, diplomats say.

In a recording aired this week by Al Jazeera television, Al Qaeda called on Algerians to snub the polls, calling them "a farce that is not different from other farces seen before in Algeria."

"If you take part in these elections, you will be sharing those apostates' flagrant act," said Abu Mussaab Abdul Wadud, leader of Al Qaeda in North Africa, in the audio tape recording that was aired by Al Jazeera Monday.

"Express your opinion and renounce these elections. You only need to boycott or abstain from voting."