At least 11 people were killed and dozens wounded when three car bombs tore through public markets in Shia provinces in southern Iraq early on Monday, medics and police sources said.
Sectarian tensions are at their highest since U.S. troops left Iraq more than a year ago and militant attacks have increased as the country's fragile intercommunal balance comes under growing strain from the civil war in neighbouring Syria.
More than 180 people have been killed since Tuesday, when security forces stormed a Sunni protest camp near Kirkuk, triggering clashes that quickly spread to other Sunni areas in western and northern provinces.
Two of the explosions on Monday took place in Amara, 300 km (185 miles) southeast of Baghdad, killing at least nine people and wounding a further 40, medics and police sources said.
The third explosion took place in Diywaniya, 150 km (95 miles) south of Baghdad, when a car bomb blew up in a public market, killing two people and wounding 27, police said.
No group immediately claimed responsibility for the attacks, but car and suicide bombings are trademarks of al Qaeda's Iraq wing, the Islamic State of Iraq.