Baghdad:  A suicide car bomb hit a joint US-Iraqi military patrol in Iraq's eastern Diyala province on Friday, killing at least eight people including US soldiers, Iraqi security sources said.

Three US soldiers and five Iraqi policemen were killed when a car packed with explosives detonated alongside the patrol near a market in the town of Jalawla, 115 kilometres north east of Baghdad, a security source in Diyala said.

One police source in Diyala said four US soldiers and four Iraqi police officers were killed, and 26 civilians were wounded. Another police source said two US soldiers and four Iraqi police were killed.

The US military did not immediately respond to requests for confirmation of US casualties.

Overall violence in Iraq has dropped sharply since the height of sectarian warfare in 2006-2007, but an inconclusive March parliamentary election has fuelled a spike in bloodshed. In Baghdad yesterday, a roadside bomb killed two civilians and wounded nine others in the southern Doura district, police said. A car bomb in the capital late on Thursday killed four people and wounded 10.

Shiite blocs merge

On the political front, Iraq's two main Shiite electoral blocs announced their merger on Thursday under a new name, National Alliance, but have yet to resolve differences over their nominee for prime minister.

Prime Minister Nouri Al Maliki's State of Law bloc, which came second in Iraq's March 7 parliamentary election, and the third-placed Iraqi National Alliance (INA), had declared in early May that they intended to merge.

A cross-sectarian coalition led by secularist former Prime Minister Eyad Allawi eked out a two-seat win in the election with strong support from minority Sunnis.

But because no bloc won an outright majority, political factions have had to negotiate alliances to gain enough seats to form a government.