GAZA CITY, Gaza Strip - As Israel's prime minister congratulated the military for assassinating Sheik Ahmed Yassin, the spiritual leader of the militant group Hamas, more than 200,000 Palestinians jammed the streets for his funeral march and vowed revenge.
Palestinians belonging to rival political factions put aside their differences to march side by side, while masked gunmen rattled off machine-gun salutes into the air to honor a man they revered as a hero and whom Israel regarded as a terrorist.
It was the largest public gathering in memory in this crowded, volatile city, where burying those killed fighting Israel has become a ritualistic pageant extolling the virtues of martyrdom, and where grief and anger become interchangeable.
Israeli Prime Minister Ariel Sharon, who has proposed withdrawing Jewish settlers and soldiers from the Gaza Strip, thanked his military for killing Yassin, whom he described as an "arch-terrorist" committed to "killing and murdering Jews, wherever they were."
Speaking to members of his Likud Party, Sharon declared that "it is the natural right of the Jewish people, like that of all nations in the world that love life, to hunt down those who rise to destroy it."
Hamas, the most lethal of the Palestinian militant groups, has carried out more than 50 suicide attacks in the past three years, taking the lives of hundreds of Israelis.
Some Israeli officials questioned the wisdom of killing Yassin, warning that reprisals by Hamas could outweigh any immediate benefits. Israeli television reported that Israel's domestic intelligence service, the Shin Bet, had opposed the assassination, arguing that it would "do more harm than good."
Palestinians marched in the West Bank and Gaza on what was declared the first of three days of official mourning. Five Palestinians, including two teen-agers, were killed in clashes with Israeli soldiers.
In Ramallah, in the West Bank, demonstrators converged on the ruined compound of Palestinian leader Yasser Arafat, who ordered flags flown at half-staff and praised Yassin, who competed with him for power and popularity.
"May you join the martyrs and the prophets," Arafat said. "To heaven, you martyr."
Yassin, who used a wheelchair, was killed yesterday when the Israeli army targeted him with missiles as he was leaving dawn prayers. Seven others were killed in the helicopter attack, including two of Yassin's bodyguards. By midmorning, the air was filled with acrid smoke from tires set alight by protesters.
"Yassin was not just Hamas," said Yousef Said, a 47-year-old Gazan standing outside Martyr's Cemetery, where Yassin was buried. "He was an international Islamic symbol who was honored to die for us."
Britain, the European Union and the United Nations condemned the assassination, saying it would inflame the conflict locally and across the Arab world. British Foreign Secretary Jack Straw said "it was very unlikely to achieve its objectives."
Egyptian officials, who have sought to negotiate a cease-fire between Israel and the Palestinians, canceled plans for Egyptian legislators to visit Israel today to mark the 25th anniversary of the peace accord between the two countries.
The Israeli army has assassinated dozens of militants in the past 3 1/2 years of fighting, arguing in most cases that the killings were the only way to stop imminent attacks. Israeli commanders have gradually expanded their target list to include militant leaders, who they argue set the agenda and orchestrate suicide bombings. Israeli leaders publicly identified Yassin in January as "marked for death."
Yossi Kuperwasser, head of the Israeli military's intelligence research department, told a parliamentary committee yesterday that killing Yassin, "in the short run, will increase feelings of revenge and will increase the motivation for attacks."
But he argued that Yassin's removal "creates a void in the Palestinian leadership that might harm the organization's activities. None of the other leaders in Hamas had his influence."
Other Israeli officials have argued that a stepped-up assassination campaign in January drove Hamas leaders underground and kept them too busy hiding to plan attacks.
Interior Minister Avraham Poraz of the centrist Shinui Party told Israel Radio that he was among a handful of Cabinet officials who cast his ballot during a secret vote last week against targeting Yassin.
"I fear we have opened up a cycle here and that many will pay for it with their lives," Poraz said. "Yassin will become some sort of martyr, a national hero for the Palestinians, and I'm very sorry to say, this won't prevent Hamas from continuing its activities."
Israeli police, on high alert, set up roadblocks yesterday and blanketed city centers with armed officers and bomb-sniffing dogs. Authorities shut down access to and from the West Bank and Gaza, barring Palestinians from leaving cities or entering Israel to work. The defense minister recommended that Israeli embassies abroad bolster security.
The streets of Jerusalem were tense but remained relatively busy, as people waited for what some defense officials said was an inevitable response from Hamas - almost as if a reprisal had been built into the equation of killing the group's leader.
Numerous attacks were reported, including one in which a Palestinian struck three people with an ax in the Tel Aviv suburb of Ranana and the stabbing of three passengers aboard a bus in Jaffa. The Lebanese militant group Hezbollah launched a volley of rockets at Israeli army positions across the border, and Palestinian militants in Gaza fired mortars and rockets at Israeli settlements and communities.
Yassin founded Hamas, an Arabic acronym for Islamic Resistance Movement, in 1987, building a group active in charitable work as well as armed conflict. It grew into a powerful organization that rivaled Arafat's party, Fatah.
Unlike Fatah, Hamas opposes negotiations with Israel and advocates the destruction of the Jewish state. Its armed wing has claimed responsibility for suicide bombings that targeted Israeli buses and restaurants.
Yassin's body was taken to the morgue at Shifa Hospital in Gaza. A member of Yassin's mosque, Mostasen Dalloul, washed the body to ready it for Muslim burial. He said Yassin's arms, legs and torso were peppered with shrapnel wounds, and that the top of his head had been blown off. His white beard had been singed black.
Yassin's body, wrapped in a shroud, was placed in a simple wooden coffin, covered loosely with a green tarp and carried from the hospital to the mosque in central Gaza and then two miles to the cemetery.
Schools and almost every shop were closed in this city of 420,000, not including another 100,000 packed into a neighboring refugee camp. Side streets were deserted, giving the city the feel of a ghost town.
But on Gaza's main thoroughfare, Omar al-Mukhtar Street, tens of thousands gathered to march or to stand on the sidewalk to watch Yassin's funeral procession.
Merchants joined in, as did children dressed in the garb of their favorite militant group. Those too young or too small to hold real guns brandished toys, though boys who appeared not yet ready to shave were seen clutching Kalashnikov rifles.
A gun-toting member of the militant Aqsa Martyrs Brigades, affiliated with Arafat's Fatah, joined the procession.
"Our response will be like an earthquake," said the 23-year- old, who identified himself only by the nom de guerre Abu Adib. "Sheik Yassin is more than Hamas. He is Palestine."
Supporters flanked by hundreds of masked militants, many armed with machine guns and missile launchers, carried Yassin's coffin to the burial site as loudspeakers blared political slogans, verses from the Quran and vows of revenge.
Participants said the crowd far exceeded the number who flocked to see Arafat when he returned from exile in 1994. Though Arafat continues to represent the Palestinians' nationalist aspirations, he is widely unpopular in Gaza, where people view the Palestinian Authority as corrupt and inept.
"This funeral is the referendum for any election that the Palestinian Authority might want to have," said Ali Ala Hassan, 50, a shoe salesman who said he supports Hamas as the only group that can win concessions from Israel.
"What got Sharon to talk about leaving Gaza?" Hassan asked. "It was what you call violence and we call resistance."