Israeli helicopters fired several missiles at targets in Gaza City early Monday, hours after Palestinian militants killed five Israeli soldiers and wounded at least five others in an attack on an army post near the Gaza-Egypt border.

Israeli military officials say their strike hit a building where militants had been working on weapons to use against Israel. No casualties were reported.

Earlier, a joint statement by the Palestinian militant groups Hamas and Fatah Hawks said suicide bombers detonated more than a ton of explosives beneath an Israeli army post, in a 600-meter-long tunnel that guerrillas had spent four months digging.

The huge blast at the Rafah crossing killed three Israeli soldiers. Two more soldiers and at least one Palestinian militant were killed in a shootout.

Some information for this report provided by AP, AFP and Reuters.