At least 12 Iraqis and three US soldiers have died in bombings and gun attacks across Iraq in the last 24 hours, officials say.
Bomb attacks have continued despite tightened security
The attacks included three car bombings in different parts of Baghdad, which killed four people and injured several.
One of the three US soldiers was hit by small-arms fire, another was killed by a roadside bomb, and the third died in an exchange of fire, the US said.
US-led forces have been carrying out a major operation to improve security.
They are attempting to stem a recent rise in violence in Baghdad, and say the situation is improving.
The US military has said a joint force of Iraqi and US soldiers has searched 31,000 buildings and 25 mosques, detained 70 suspected terrorists and seized 529 weapons in the past two weeks.
Among those killed in Thursday's violence were two policemen, hit by a roadside bomb.
A police chief in charge of patrols in eastern Baghdad survived a car bomb attack in the city that injured five officers travelling in his convoy.