(BBC) -- The latest results from Iraq's parliamentary poll show a tight race emerging between Prime Minister Nouri Maliki and his main rival, Iyad Allawi.

With 80% of votes counted, the secular Shia-Sunni Iraqiya coalition led by Mr Allawi, a former prime minister, has a narrow overall lead for the first time.

But Mr Maliki's State of Law alliance remains ahead in Baghdad and Basra.

The BBC's Andrew North, in the capital, says the picture could well change by the time all the votes are counted.

Results from refugee voters outside Iraq, and special pre-election voting by Iraqi security forces have still to be announced, and they could dramatically affect the outcome of the parliamentary poll, our correspondent says.

With neither coalition able to win an overall majority, it is likely to mean talks on forming a new government will be long and difficult, he adds.

Minority Sunnis

Mr Allawi's Iraqiya coalition is ahead in five of Iraq's 18 provinces, and his nationwide lead is only 9,000 votes.

It is proving popular among minority Sunni Muslims resentful of the dominance of Shia religious parties since 2003.

Mr Maliki's State of Law alliance is meanwhile ahead in seven provinces.

Behind, the frontrunners are the Shia-led Iraqi National Alliance (INA) and the Kurdistan Alliance, formed by the Kurdistan Democratic Party (KDP) and Patriotic Union of Kurdistan (PUK).

Vote counting since the 7 March election has been dogged by technical problems and claims of fraud.

On Wednesday, Mr Maliki's party asked for a recount in Baghdad province - where its lead has steadily narrowed - following claims that votes were being manipulated in favour of an unnamed competitor.

The Independent High Electoral Commission (IHEC) has said the count was fair and included multiple checks against fraud.

Preliminary election results are expected in the next few days, while the final results - after complaints have been investigated - are due by the end of the month.

The election comes less than six months before the US military is scheduled to withdraw all of its combat troops from Iraq.