Israeli artillery fires a shell near Kibbutz Nahal Oz, just outside the northern Gaza Strip

 Israeli forces have launched a second day of air strikes in the Gaza Strip, and arrested more than 200 members of Hamas and the Islamic Jihad in the West Bank. The operation is aimed at stopping Palestinian rocket attacks.

Israeli helicopters fired missiles at buildings used by Palestinian militants in the Gaza army went into action after militants in Gaza fired more than 40 rockets at Israeli towns. Prime Minister Ariel Sharon told his Cabinet that he has ordered a prolonged military operation to halt the rocket attacks.

"We will use all means necessary to hit the terrorists, their weapons and their bases," Mr. Sharon said.

Cabinet Minister Yitzhak Herzog said Israel withdrew from Gaza, and returned to the international border, and now there is no excuse for Palestinian attacks.

Militants fired rockets at Israel after at least 15 Palestinians were killed in an explosion during a Hamas military parade in Gaza on Friday. Hamas blamed Israel, but the Palestinian Authority said the blast was caused by militants who mishandled explosives.

Palestinian officials condemned the Israeli raids, but they also criticized Hamas for parading weapons. Palestinian chief negotiator Saeb Erekat appealed to both sides to uphold the cease-fire.

"And we urge the international community's direct intervention; direct intervention in order to maintain the quiet, in order to maintain the cessation of violence," said Mr. Erekat.

The international community had hoped that Israel's Gaza pullout would revive the "Roadmap" peace plan. But just two weeks after the withdrawal, the cease-fire is in danger of collapse.