At least 30 people have died and many more were hurt after a suicide bomber targeted a funeral in a Shia town north of the Iraqi capital, Baghdad.
Police say the attack in Khalis, in Diyala province, took place inside a tent where mourners had gathered.
Earlier, the US said three US soldiers and a translator died in a Baghdad bomb at the weekend and another nearby was shot dead. Also a marine died in Anbar.
April saw over 100 US deaths, making it one of the deadliest months since 2003.
Additionally, four Iraqi civilians were killed by a suicide bomber in Baghdad, one of several violent incidents.
Five people died in an explosion in the southern city of Basra on Sunday.
Initial reports suggested it was a car bomb attack, but the British military said the blast appeared to have been caused by militants accidentally detonating explosives they were moving.
Two people were killed and 15 wounded when a bus bomb exploded in a road tunnel, damaging a main artery in western Baghdad.
Media reports say the US monthly death toll has topped 100 five other times since the invasion of Iraq in March 2003.
In February, US and Iraqi forces launched a major security crackdown in Baghdad seen as a final attempt to halt a plunge into all-out civil war between Iraq's majority Shia community and the once-dominant Sunni Arab minority.