Israel killed Hamas founder Ahmed Yassin in a helicopter missile strike outside a Gaza City mosque Monday, prompting threats of unprecedented revenge by Palestinian militants against Israel and the United States.
Yassin was the most prominent Palestinian leader killed by Israel in more than three years of fighting, and his assassination was seen as a major escalation.
More than 200,000 Palestinians, some carrying billowing green Hamas flags, flooded the streets for the funeral procession, the largest gathering in Gaza City in recent memory. Thousands also took to the streets in the West Bank.
Mourners jostled to touch Yassin's flag-draped coffin, and women ululated and threw flowers and candy. Two Israeli helicopters flew above, and the sky was blackened from the smoke of tires set ablaze in the streets by protesting Palestinians.
At the cemetery, Yassin's body was carried between two rows of 200 militants armed with anti-tank missiles and machine guns.
"Words cannot describe the emotion of anger and hate inside our hearts," said Hamas official Ismail Haniyeh, a close associate of Yassin.
Israeli Prime Minister Ariel Sharon called Yassin the "mastermind of Palestinian terror" and a "mass murderer who is among Israel's greatest enemies."
Sharon said Israel will press ahead with its war on terror, signaling more targeted attacks and raids. "The war against terror has not ended and will continue day after day, everywhere," he said.
In addition to Yassin, 12 Palestinians were killed Monday, seven in the airstrike, four in clashes with Israeli troops and one while handling explosives.
U.S. national security adviser Condoleeza Rice said Washington had "no advance warning" of the attack. Rice said she knew of no consultations between Sharon and President Bush about any plan to target the sheik.
But Rice, asked about U.S. reaction to the attack during an interview on NBC, said, "Let's remember that Hamas is a terrorist organization and that Sheik Yassin has himself, personally, we believe, been involved in terrorist planning."
State Department spokesman Lou Fintor said U.S. officials were in touch with Israeli and Palestinian authorities. "The United States urges all sides to remain calm and exercise restraint," he said.
Israeli Foreign Minister Silvan Shalom, after meeting with Vice President Dick Cheney, called the attack on Yassin a matter of self-defense and said Palestinians "will pay for their crimes. They will pay for the instructions they are giving to the suicide bombers."
Hezbollah guerrillas shelled Israeli positions in a disputed border area Monday for the first time in five months, triggering an Israeli airstrike and artillery fire, Lebanese security officials said. The Israeli army said the guerrillas fired an anti-tank and there were no reports of injuries or damage.
Israeli helicopters fired three missile as Yassin, his bodyguards and dozens of others left a mosque in Gaza City at daybreak Monday. Yassin, a quadriplegic who uses a wheelchair, and seven others were killed, including several bodyguards. Seventeen people were wounded.
Only a charred metal seat and a twisted wheel were left of his wheelchair and a blood-soaked brown shoe lay in the street. "Two or three people were lying next to him on the ground. One was legless," said taxi driver Yousef Haddad, who had rushed out of a nearby grocery when the missiles shook the Sabra neighborhood.
Fearing reprisal attacks, Israel sealed off the West Bank and Gaza and confined many West Bank Palestinians to their communities. The Rafah border crossing between Gaza and Egypt was also closed. Troops reinforcements were sent to Gaza, and security forces in Israel were placed on high alert.
Three more Palestinians were killed in Gaza later Monday in clashes with Israeli troops, and one was killed while handling explosives.
Sharon, a former army general, was updated throughout the operation.
"The Israeli air force this morning killed the mastermind of all evil, Ahmed Yassin, who was a preacher of death," said army spokeswoman Brig. Gen. Ruth Yaron.
The Yassin assassination was seen as an enormous gamble by Sharon, who is trying to score a decisive victory against Hamas ahead of a possible Israeli withdrawal from Gaza, but risks triggering a dramatic escalation in bloodshed that could turn the public's mood in Israel against him.
Sharon's critics in Israel warned that the Yassin killing could be seen as an attack by Israel on Islam and unnecessarily widen the circle of conflict.
The Palestinian Authority said in a statement that "Israel has exceeded all red lines with this cheap and dirty crime," and declared a three-day mourning period.
Flags at Yasser Arafat's headquarters in the West Bank town of Ramallah were lowered to half-staff, and the Palestinian Cabinet held an emergency session. Yassin was Arafat's biggest political rival, but Arafat has always been careful not to confront the Hamas leader openly.
Cabinet ministers stood as Arafat recited a Muslim prayer for the dead. The Palestinian leader, referring to Yassin, then added: "May you join the martyrs and the prophets. To heaven, you martyr."
Palestinian Prime Minister Ahmed Qureia said the Palestinians have lost "a great leader."
Earlier Monday, about 2,000 demonstrators gathered at Arafat's headquarters, calling for revenge. Arafat remained inside, apparently fearing he too might be targeted by Israel.
However, an Israeli security official said there were no immediate plans to target Arafat, and that Hamas was the focus of Israel's current offensive.
Tens of thousands of Palestinians marched in the West Bank in protest, including about 15,000 people in Nablus. "This morning, dozens came to us volunteering to be suicide bombers and we will send them at the right time," one masked man said at the rally.
Thousands more demonstrated in the town of Jenin. In the West Bank town of Hebron, Palestinians threw stones at Israeli soldiers, who fired tear gas.
West Bank schools were closed, and a one-day commercial strike was declared. In the Israeli prison camp of Ketziot, hundreds of Palestinian prisoners rioted briefly, setting tents on fire and throwing stones at soldiers.
The Israeli army chief, Lt. Gen. Moshe Yaalon, met with army commanders in Tel Aviv, and more forces were ordered to the Gaza Strip.
Hamas threatened a harsh response. "Yassin is a man in a nation, and a nation in a man. And the retaliation of this nation will be of the size of this man," said Abdel Aziz Rantisi, a prominent Hamas leader in Gaza who himself escaped an Israeli assassination attempt last June.
For the first time, Hamas also threatened the United States, saying America's backing of Israel made the assassination possible. "All the Muslims of the world will be honored to join in on the retaliation for this crime," Hamas said in a statement.
In the past, Hamas leaders have insisted their struggle is against Israel and that they would not get involved in causes by militant Muslims in other parts of the world. Monday's statement suggested that Hamas might seek outside help in carrying out revenge attacks, since its capabilities have been limited by Israeli military strikes.
Rival militant groups also threatened revenge.
The assassination was widely condemned in the Arab world and by some European countries. Egypt canceled a trip by legislators and other dignitaries to Israel, which had been planned for later this month to mark the 25th anniversary of the signing of a peace treaty between the two countries.
British Foreign Secretary Jack Straw said the assassination "is unacceptable, it is unjustified and it is very unlikely to achieve its objectives."
The attack also drew criticism in Israel. Opposition leaders and even some members of Sharon's government warned the killing would increase the cycle of violence.
"My great fear is that this will be understood as an attack against a religious leader," said Interior Minister Avraham Poraz of the centrist Shinui Party.
Israel had previously tried to kill Yassin in September when a plane dropped a bomb on a building where he and other Hamas leaders were meeting. Yassin escaped with a small wound to his hand. One Israeli official recently said Yassin was "marked for death."
In more than three years of fighting, Hamas and the Israeli military have seemed to trade blows, with Hamas carrying out suicide bombings and other attacks, and Israeli responding with airstrikes and ground raids.
Sharon's recent declaration that Israel may leave Gaza has prompted both sides to intensify fighting, to try to claim an Israeli withdrawal as a victory.
At Shifa Hospital in Gaza City, where Yassin's mangled body was taken, masked gunmen shot in the air. Cars drove through the streets blaring calls for revenge over loudspeakers.
Yassin founded Hamas in 1987. He was held in Israeli prisons for several years before being released in 1997. Israel blamed him for inspiring the Hamas bombers who have killed hundreds of Israelis.