One Iraqi was killed and five wounded on Saturday when clashes broke out between US forces and unidentified fighters in Ramadi, the city hospital said.
The clashes broke out as US marines were conducting searches in the city, 113km west of Baghdad, according to Dr Dhia Abd al-Karim of Ramadi General Hospital.
The US military had no immediate information on the incident. Ramadi has seen repeated bombings and clashes in recent weeks.
Elsewhere, two Iraqis were shot and killed by US forces during a deployment of dozens of US troops in heavy vehicles in Abu Ghraib, west of Baghdad, Aljazeera has learned.
A number of army vehicles have been deployed at entrances to Haifa Street in the middle of the capital.
Shootings were heard in the area.
In the Green Zone, a rocket or mortar exploded, sending up a large cloud of smoke over the heart of the American and Iraqi government quarters.
The blast occurred about 1:45pm (1045 GMT). There was no immediate report of damage or casualties.