The Israeli army has demolished more than 30 homes in the Gaza Strip following a raid by Palestinian gunmen on a military post that left four soldiers dead.

Under cover of darkness, Israeli bulldozers and armored vehicles rumbled into the Rafah refugee camp in Gaza. The bulldozers flattened houses, leaving dozens of Palestinians homeless.

The army says Palestinians threw grenades and fired rifles toward the troops during the incursion, but no one was injured. The military says the buildings were used by Palestinian gunmen to fire at Israeli forces.

The soldiers later pulled out of the camp, leaving behind huge piles of rubble, twisted metal and broken furniture where homes once stood. Weeping residents of the refugee camp sifted through the debris trying to recover their belongings.

Earlier, the army destroyed Palestinian security posts and closed three naval buildings in Gaza.

The moves came after two Palestinian gunmen who lived in the Rafah camp attacked a nearby army post inside Israel, killing four soldiers. The two gunmen died during the assault.

Israeli officials say a total of eight assailants were involved in the attack. They included six Palestinians who remained in Gaza intentionally setting off alarms along a high-security border fence to divert troops from the outpost that was targeted.

The militant Islamic group Hamas claimed responsibility for the incident, which shattered a few weeks of relative calm following Palestinian leader Yasser Arafat's call for an end to suicide bombings and armed attacks against Israelis.

The Palestinian Authority condemned the assault on the soldiers, but Israeli Prime Minister Ariel Sharon says Mr. Arafat is responsible for the incident.

Mr. Sharon says Israel will review its policy toward the Palestinians following the latest bloodshed and the seizure of a freighter carrying a large amount of weapons Israel says were being shipped to the Palestinians. Israeli commandos last week found 50 tons of munitions on board, including rockets and anti-tank weapons.

Palestinians have denied involvement in the shipment, but the boat's captain says he received his orders from officials in the Palestinian Authority.

The continuing violence is threatening U.S. led efforts to broker a permanent truce to end more than 15 months of fighting between Israel and the Palestinians.

Earlier this week, U.S. mediator Anthony Zinni left the region on a hopeful note, saying both sides were trying to make a cease-fire work.