At least 24 people were killed in 10 blasts across Iraq on Sunday, including a car bomb outside a French consular building.
Sunni insurgents and al Qaeda have launched a series of major attacks this year in an attempt to stoke the kind of political and sectarian tensions that drove the country to near civil war in 2006-2007.
The most serious attack happened overnight in Dujail, 50 km (30 miles) north of Baghdad, when gunmen and a suicide bomber driving a car attacked a military base, killing 11 soldiers and injuring seven, police sources said.
One car bomb exploded outside the French consular building in the usually stable city of Nassiriya, 300 km (185 miles) south of Baghdad, wounding two people, police said. Another car bomb also detonated in the city, killing two and wounding three.
More people were killed in several other blasts across the country in the towns of Kirkuk, Samarra, Basra and Tuz Khurmato.
The government, riven by infighting among Sunni, Shi'ite and Kurdish political factions, is still struggling to battle Islamist militants and an al Qaeda affiliate nine months after the last U.S. troops left.
Iraq's local al Qaeda wing, Islamic State of Iraq, has claimed responsibility for other major attacks on security forces and Shi'ite neighbourhoods. But former members of Saddam Hussein's outlawed Baathist party and other Sunni Islamist groups are also fighting the government.
Nobody has yet claimed responsibility for Sunday's attacks.
Tension in Iraq's delicate power-sharing government, and a resurgence of the al Qaeda group, have raised fears of a return to widespread violence, especially as Iraq struggles to contain spillover from the growing conflict in neighbouring Syria.