Raanana, Israel ? As the Hamas militant group chose new top officials Tuesday in place of Sheik Ahmed Yassin, Israel’s government threatened to kill the organization’s entire leadership, security sources told news organizations in Israel Tuesday.

Following a meeting by Israel’s top security officials, “everyone is in our sights,” said police minister Tzachi Hanegbi.

And Israel’s army chief suggested that the government was moving closer to an attempt to kill Palestinian Authority President Yasser Arafat. Asked whether Israel’s offensive might strike Arafat or the head of Lebanon’s Hezbollah guerrillas, Hassan Nasrallah, the Israeli army commander, Lt. Gen. Moshe Yaalon, said: “I think … they understand that it is nearing them.”

Tuesday did not bring the explosion of new violence that was immediately feared following Israel’s missile attack Monday that killed Yassin. The day’s bloodshed came in southern Lebanon, where Palestinian guerrillas fired rockets toward Israel, which launched an air strike in response that Lebanese security sources said killed two Palestinians.

The order to kill a wider circle of Palestinian militant leaders came after a meeting late Monday among Israel’s top security officials, news reports said.

Israel defended its killing of Yassin in debate at the U.N. Security Council after the United States blocked a resolution that would have condemned the act. U.S. diplomats insisted on including Hamas attacks on Israel in the condemnation.

Israel killed Yassin in part because of Hamas’ March 14 attack on the port of Ashdod, not only because it killed 10 Israelis but also because of what the attack might have done. The suicide bombing came within striking distance of hazardous chemicals and fuel storage tanks.

Throughout the 3 1/2-year-old conflict, Palestinian militants have focused their attacks on civilian targets such as buses, cafes and restaurants. But the port facility contains the ingredients for what officials call a “mega-terrorist attack,” involving the release of deadly chemicals or a catastrophic explosion.

Israeli female soldiers cross an unusually empty street on their way to be deployed in downtown Jerusalem. Israel's killing of Hamas spiritual leader Sheik Ahmed Yassin in a helicopter missile strike in Gaza City has prompted threats of unprecedented revenge by Palestinian militants. Amid increased security, army troops were reinforcing police units Tuesday in Israel's capital.

Meanwhile, President Bush said Tuesday he hoped to send high-level emissaries to the Middle East next week to see if anything can be done to revive derailed Israeli-Palestinian peace negotiations. He also expressed concern about a Hamas threat against the United States.

“We take every threat seriously in this administration,” Bush told reporters after the Islamic militant group threatened retaliation against both the United States and Israel.