A US soldier was reported killed in insurgency-plagued western Anbar province.
Many of the attacks targeted the country’s Shiite-led security forces, accused by Sunni Arabs of abuses against them under the cover of fighting the Sunni-driven insurgency.
The bloodiest attack happened in Baqouba, where a car bomb targeting a police patrol exploded near a market, killing six people and injuring 23, including four patrolmen, police said.
Bombs and mortar fire also rocked the capital, ending a relative lull over the weekend.
A suicide car bomber hit an Interior Ministry convoy in eastern Baghdad, killing two members of the security force and injuring three, police said
Another bomb exploded as a police patrol was driving through a northern Baghdad neighbourhood, killing one officer and a civilian bystander, officials said.
Two more policemen were killed when a car bomb exploded in a residential street.
Police found at least four more bodies that were shot in the head and dumped in parts of Baghdad.