Iraqi authorities say attacks across the country have killed seven people, including a 10-year-old boy, the latest in a surge of violence.

Police said in Monday's deadliest attack, mortar shells exploded near people swimming in the Tigris River, trying to escape the summer heat. Four people were killed, including the boy, and 11 others were wounded.

In the northern city of Kirkuk, a policeman was killed and 11 other people were wounded, including four civilians, when a car bomb went off near a passing security patrol.

Also, gunmen sprayed a security checkpoint with bullets just south of Baghdad, killing two soldiers and wounding four others.

Hospital officials confirmed the death toll. All officials spoke on condition of anonymity because they were not authorized to talk to reporters.