Four people, including police officers, have been killed in a series of attacks in Iraq, authorities said today.

In the first attack, two policemen were gunned down in a drive-by shooting near the northern city of Mosul. Another officer was injured, police officials said.

In the oil-rich city of Kirkuk, a civilian driver was killed when his truck hit a roadside bomb.

And another roadside bomb exploded just south of the capital, Baghdad, killing a policeman and injuring three others while they were on patrol.

Medics in nearby hospitals confirmed the casualties.

Violence in Iraq has ebbed but insurgent attacks are still frequent.