A triple suicide bombing in the Kurdish town of Qara Tapah has killed at least 50 people.
Many of dead were members of the Kurdish security forces and civilians enlisting to the military.
Islamic State (IS) has claimed responsibility for the attack.
And the police chief of Iraq's Anbar province, where IS militants are advancing, has been killed by a roadside bomb, officials say.
Major General Ahmed Saddag was killed when the bomb targeted his convoy near the provincial capital Ramadi.
IS militants have seized large parts of Iraq and Syria in recent months, pushing back Iraqi forces.
A local source said the police chief was on patrol inspecting security forces in the Al-Bu Risha area of Ramadi when two roadside bombs went off.
Anbar province is the home of a growing insurgency by Sunni militants, including IS.
At a government compound in Qara Tapah, north-east of Baghdad, three bombs killed 50 people - many of them reported to be veteran fighters signing up for the battle against IS.
A suicide bomber detonated his charge at the entrance to clear the way for two more car bombs that followed.
The mayor of the town, Wahab Ahmed, said the attack was aimed at his office.
On Saturday, a series of car bombs exploded in mainly Shia areas of the Iraqi capital Baghdad, killing at least 38 people.
At least 75 people have been killed in attacks in various Iraqi cities over the weekend.
A US-led coalition continues to carry out air strikes against IS targets in Iraq and Syria.
In the besieged Syrian town of Kobane, fighting between IS militants and Kurdish forces continued on Sunday.
US Defence Secretary Chuck Hagel said that US-led air strikes had made progress against the militants, but that they still occupied areas on the town's outskirts.
More than 500 people are reported to have been killed in a month of conflict in and round the town, which borders Turkey.