Three Palestinians were killed in an explosion in the southern Gaza Strip city of Rafah today.
Two of the dead were militants. The third was an off-duty policeman who owned a shop in Rafah, a militant stronghold near the Egyptian border which has been the scene of frequent clashes.
At least 15 people were wounded, including a Reuters cameraman, who was hit in the hand by shrapnel.
Witnesses said they believed the blast was caused by a missile fired by Israeli helicopter gunships. The Israeli army said it was checking the report.
"There was a big explosion, bodies fell on us and there was shrapnel flying," said one witness.
Clashes broke out in Rafah overnight when Israeli tanks and troops moved in to look for tunnels used to smuggle arms from Egypt during nearly four years of Israeli-Palestinian conflict.
Israeli helicopter gunships have frequently fired missiles at militants in Gaza. Palestinians have also sometimes been killed when their explosives detonated prematurely.