At least 38 people have been killed in a series of co-ordinated attacks across Iraq, officials say.
Two car bombs in the predominantly Shia city of Kerbala are reported to have killed at least 13 people.
Another car bomb near police headquarters in the northern city of Kirkuk killed seven people, according to hospital sources.
The attacks come ahead of next week's Arab League summit to be held in the capital, Baghdad.
Security forces in Iraq have been placed on high alert ahead of the summit.
The attacks also coincide with the ninth anniversary of the beginning of the US-led invasion of Iraq.
The summit is seen as the country's debut on the regional stage following the withdrawal of US troops in December.
It is widely thought that the attacks are intended to undermine confidence in the government at a crucial time, says the BBC's Peter Biles.
Elsewhere, there were attacks in a number of other Iraqi towns.
There are also reports of a car bomb blast in the capital, Baghdad, which is said to have killed at least two people, and of an attack outside the foreign ministry, as well as attacks in Hilla and Latifiya in the south of the country.