A suicide bomber Monday attacked a joint patrol of NATO and Afghan forces in southern Afghanistan, killing a policeman, officials said. The bomber rode a motorbike towards the patrol, opened fire and killed one policeman, the Helmand governor's office said in a statement. The attack took place in Sangin district, said the statement quoted by the German Press Agency "DPA". The bomber detonated his explosives-packed vest when he came close to the patrol, the statement said. There were no causalities among the foreign forces, it added.