US marines killed 25 guerrillas and captured 25 during several hours of fighting in the western Iraqi city of Ramadi, a military statement said on Thursday.

A total of 13 US marines and one soldier were also wounded in the clashes, said the statement.

The fighting erupted Wednesday afternoon when insurgents attacked a marine convoy with a roadside bomb and then opened fire with assault rifles and rocket-propelled grenades to the US forces.

About 100 insurgents were involved in the clashes later.

"Quick reaction forces were requested and responded to further repel the attack. Marines and soldiers on the ground were also backed by aviation assets that provided fire support," the statement said.

Ramadi, some 100 km west of Baghdad, is one of the flashpoint cities, which has witnessed a series of insurgency against the US-led multinational forces in the violence-torn country.