Coalition talks between the two main political movements in Iraq have been suspended as the country struggles to form a government.
The former prime minister Iyad Allawi’s Sunni-backed alliance broke off the tentative negotiations.
It has launched an attack on the current premier Nuri al-Maliki, accusing his Shi’ite-led group of sectarianism.
Five months after the elections in March, the parties still have not reached agreement on a coalition.
Allawi is claiming the right to form a government after his group came top with 91 seats, two more than Maliki’s alliance.
Meanwhile five people have been killed and at least nine injured in a bomb attack north-east of Baghdad on a bus carrying Iranian Shi’ite pilgrims.
It follows other deadly attacks over the past few days.
The violence is down compared to a few years ago. But it is thought that insurgents have been trying to take advantage of a power vacuum, with no new government in place and Washington planning to cut the number of troops.