Car bombs have exploded in mainly Shi'ite sections of Iraq's capital, and in the southern city of Basra, killing at least 43 people and wounding dozens more.
Officials say at least eight car bombs blew up in Baghdad on Monday, some at market places and crowded bus stops. Two others went off in Basra, which is predominantly Shi'ite and one of the largest cities in Iraq.
The attacks come amid a spike in violence and high tensions between Iraq's Shi'ite majority and Sunni minority.
Bombings and other violence have killed more than 150 people in the past week, including 70 who died Friday in a series of bombings targeting Sunnis.
For months, Iraq's Sunnis have been protesting against Prime Minister Nouri al-Maliki, accusing his government of ignoring their needs and targeting them for arrest.
The unrest has raised fears of a return to the sectarian fighting that left tens of thousands dead in 2006 and 2007.
Violence has fallen from that peak, but the United Nations said 712 people were killed in April, making it the deadliest month in Iraq since June 2008.