At least 40 people have been killed and 70 hurt in a car bomb attack on a funeral in the Iraqi town of Falluja.
The suicide bomber drove into a large crowd of mourners
The man being buried was part of an alliance of tribal leaders working with the authorities against al-Qaeda.
In Baghdad, gunmen reportedly stopped a bus at a fake checkpoint in a Shia district, killing 11 passengers.
Meanwhile, Iraq's PM has named six new cabinet ministers to replace supporters of the radical Shia cleric, Moqtada al-Sadr, who resigned last month.
Prime Minister Nouri Maliki said the nominees were independent technocrats who would demonstrate that the government was democratic and professional.
"If we are late in announcing the names it is because we reviewed many names and CVs," he told parliament.
"We believe these nominees are the best we can get."
Sunni Arab leaders have repeatedly criticised the Shia-dominated administration for discriminating against their community, threatening to resign from government unless their grievances were addressed.
Parliament is to vote on Sunday on whether to approve the new ministers' appointments.
Series of attacks
Earlier, a suicide bomber used a car packed with explosives to carry out the attack on the funeral of Allawi al-Isawi in Falluja.
The bomber drove into a large crowd of mourners as they walked down a street holding Mr Isawi's coffin before blowing himself up.
Mr Isawi was one of two men killed earlier on Thursday who were linked with a tribal alliance that has been working with US and Iraqi forces against militants linked to al-Qaeda in Iraq in the area.
Falluja, 65km (45 miles) west of Baghdad, is the capital of Anbar Province, an area that has been a stronghold for the Sunni Arab insurgents.
The BBC's James Shaw in Baghdad says the fact that Sunnis are killing other Sunnis in such numbers in the province suggests the fight for control between al-Qaeda in Iraq and local tribes has reached a new level of intensity.
Meanwhile, gunmen set up a checkpoint and shot dead 11 passengers aboard a minibus in Husseiniya in North Baghdad, police have said.
The attackers then hid a device among the bodies which detonated when police officers arrived at the scene, killing two civilians and wounding four others.