Partial tally from Iraq's 18 provinces showed the coalition headed by Prime Minister Nouri Maliki taking the lead in two southern provinces of Najaf and Babil, while the secular Iraqiya bloc led by former Prime Minister Iyad Allawi was ahead in two provinces of Diyala and Salahuddin.

But with only 17% to 30% of the votes counted in each of those provinces, the results are inconclusive.

No party is expected to win an outright majority nationally, and the bloc that forms the next government probably will have to do so in coalition with other parties.

Maliki is expected to do well in the nine majority Shia provinces of the south, with Allawi dominating the vote in the four mainly Sunni provinces of the north and center.

The strength of Maliki's lead in Babil and Najaf suggested that his political party may be set to win the most seats in parliament.

However, the vote in Baghdad which elects 68 lawmakers will be crucial in determining the eventual winner.