Sixteen people died and another 50 were injured in an explosion at a police training base about 230km (140 miles) to the west of Baghdad.

Soon after a suicide bomber killed four Iraqi guards and injured six in a blast at a security checkpoint.

The attacks happened a few hours after US military officials said they had captured an important rebel fighter.

He is thought to be linked to a man called Abu Musab al-Zarqawi who wants foreigners out of Iraq.

A spokesman for the US military said the man, who has not yet been named, was caught along with five other men in a night raid on a building in the Iraqi city of Falluja.

US air raids

The bombings were part of another day of violence in Iraq.

There are reports of an attack in the Green Zone in Baghdad, where US forces and the Iraqi government are based, although no casualties were reported.

And US planes bombed Falluja overnight on Friday.