US forces killed 46 people, wounded 18 and captured eight others in clashes in Samarra, Iraq, on Sunday, according to reports.

The BBC said five US soldiers and a civilian were wounded in the clashes that "raged as militants made a series of attacks on (two US) convoys in the city".

Some of the attackers appeared to be wearing the black uniforms of the Fidayeen Saddam, the CNN quoted Master Sgt Robert Cargie, a spokesman for the US Army's 4th Infantry Division, as saying.

Cargie said one convoy was attacked on the east side of the city and the other while in the west.

The attackers set off explosive devices as the convoys approached, and opened fire from rooftops and alleyways, Cargie said.

The US troops responded with cannon fire from tanks and armoured personnel carriers, he added.

US armour steamrolled over a makeshift barricade put up to block one convoy, he said.

The spokesperson said that an hour later four men in a black BMW fired at members of a US combat engineering battalion. The soldiers returned fire, wounding and capturing them.

Samarra is within the so-called "Sunni triangle", the heartland of Saddam Hussein loyalists.