GAZA, July 23 (UPI) -- Many thousands of angry Palestinians surged through the streets of Gaza Tuesday for the funeral of Islamic Hamas leader Sheikh Salah Shehada and 14 other Palestinians who were killed overnight when a missile fired from an Israeli army F-16 fighter blew up Shehada's apartment building.
Mourners included supporters and militants of the five main Palestinian factions -- Fatah, Hamas, Islamic Jihad, the Popular Front for the Liberation of Palestine and the Democratic Front for the Liberation of Palestine.
"Sleep well, martyrs, sleep well, Sheikh Shehada," cried one militant. "Your people will gain revenge soon for your blood."
Each faction was led by masked members who carried a variety of weapons, firing them into the air as they chanted together, "Death to Israel, death to America." Supporters waved the factions' characteristic flags and overall, Israeli and Palestinian estimates of the crowd ranged from 100,000 to 250,000.
The bodies were carried on the shoulders of the mourners who walked along Gaza City's main street, heading toward the bombarded building, then on to the main mosque of Gaza City for prayers. The procession ended up at Gaza's cemetery for burial.
The slain included eight children ranging up to 11 years of age. The body of the youngest, a 2-month-old girl, was wrapped in a Palestinian flag and was carried by a Palestinian militant who was carried on the shoulders of another militant.
Shehada has been wanted by Israel for several years for leading the armed wing of Hamas that was behind a series of attacks against Israel over the last few years.
"Israel now is not only involved in troubles with Hamas or Islamic Jihad, Israel now is involved in troubles with all the Palestinian people," said Imad Salman, one of the mourners. "Every Palestinian will seek revenge for their deaths."
The Israeli air strike also injured about 150 people.
"It is a condemned massacre and an awful crime carried out against our innocent children," Palestinian Authority President Yasser Arafat told reporters Tuesday.
"This crime can never be expressed in words. We will commit acts to express it," said Sheikh Ahmed Yassin, the spiritual leader of Islamic Hamas.
The attack, which happened hours after Yassin had offered what analysts said was an olive branch to the Israelis, drew international criticism.
Senior Israeli officers said Tuesday that Shehada was a top terrorist responsible for the death and injury of hundreds of Israelis and thus a legitimate target.
The Israeli army's chief of operations, Maj. Gen. Dan Harel, told a news conference in Jerusalem on Tuesday that the air force fired one precision rocket at Shehada's home, but was unaware that other family members were also in the building. Harel said Israel would not have carried out the attack had it known that civilian deaths would be involved.
Several days ago Israel had two F-16s over the area ready for an attack that was called off because Shehada was accompanied by one of the children, the reporters were told.
Shehada was founder and leader of the military wing of Hamas, known as Izel Dein Al Qassam. He had been the No. 1 man on the Israeli military's wanted listed list for two years and Israeli security sources said he personally approved or planned most of the attacks carried out by Hamas in the Gaza Strip.
Another Hamas leader, Mahmoud Al Zahar, said that the strike "represents a new stage of the conflict with the enemy," adding that the next stage "would be a horrible revenge for this crime."
Other Palestinian militant groups also vowed retaliation. Islamic Jihad announced in a statement distributed in Gaza that "every restaurant, every bus and every public place in Israel will be a target for our mujahedin (holy warriors)."
The al Aqsa Martyrs Brigades, a militia associated with Arafat's Fatah movement, said the attack made any resumption of talks with Israel inconceivable.
"Our response to the Israeli crimes will be tough and violent, and our attacks against these criminal occupiers will be resumed soon," a statement from the group said.
The attack drew protests locally, where a general strike brought the Gaza Strip and the West Bank to a standstill, regionally and from among the international community, including the United Nations and the United States.
"Israel has the legal and moral responsibility to take all measures to avoid the loss of innocent life; it clearly failed to do so in using a missile against an apartment building," said a statement from U.N. Secretary-General Kofi Annan's office.
At the White House Tuesday, spokesman Ari Fleischer called the attack "heavy-handed" and added, "The president's concern here is that there is a loss of innocent lives."
He said: "The president has been, and will continue to be, the first to defend Israel -- in this case, the president sees it differently. This message will be conveyed to Israeli authorities, and the president regrets the loss of life."
Israel radio said "senior political sources in Jerusalem" -- usually code for the prime minister's office -- rejected criticism of the attack, saying Israel was "acting within its right to self-defense."
Protests of the air strike spread throughout the Arab World. Egypt's Foreign Minister Ahmed Maher called it "a crime by all means" because it clearly targeted civilians and accused Israel of "closing all doors of hope and action for peace." In Tehran, a spokesman for Iran's Foreign Ministry called for an arms embargo on Israel, and in Amman, the Jordanian government said in a statement, "Using F-16 airplanes is a clear expression of excessive use of killing and destructive means."
Hundreds of Palestinian refugees demonstrated in their shantytowns in Lebanon. The refugees took to the streets in several camps near the port cities of Tyre and Sidon in south Lebanon. Some waved black flags in a sign of mourning, while others shouted slogans against Israel and the United States.
Witnesses said an F-16 jetfighter fired a missile that leveled several homes in a Gaza City neighborhood. Palestinian officials at Shifa Hospital in Gaza said Shehada, his wife and three of his children were killed, in addition to 10 other people.
On Monday, Yassin announced that Hamas would be willing to consider ending its campaign of suicide bombing attacks against Israel, if Israel withdrew from the West Bank, ended targeted killings of militant leaders and stopped demolition of their homes.
"Once the occupation ends all these measures, we are ready to positively study stopping martyrdom operations (suicide bombings)," Yassin told reporters as he met with three top Hamas leaders in Gaza.
(Joshua Brilliant in Jerusalem contributed to this report.)