Israeli tanks and helicopters were in the general area of the blast in al-Zahra, on the outskirts of Gaza City not far from the Jewish settlement of Netzarim. But the Israeli army said it had not fired at any car and its soldiers were not in the immediate area of the explosion.
Instead, a military source said an army helicopter had fired machine-gun warning shots earlier near the area where Palestinian gunmen were firing at soldiers.
The Palestinian Public Security directorate in Gaza, after first saying the car was destroyed in an Apache helicopter missile strike, issued a statement saying further investigation revealed the damage was from a tank shell.
Palestinian witnesses said that among the victims was the driver of a nearby motorcycle also moving along the Gaza coastal road. It wasn't clear if the motorcyclist was injured or among the dead.
Ibrahim al-Musder, director of Al-Aqsa Martyrs Hospital in nearby Deir el-Balah, said the remains of four people were brought in along with one injured person.
"The bodies of the people killed arrived in very bad shape, which makes it hard for the moment to identify them," al-Musder said.
The Hamas militant group claimed in a call to The Associated Press in Gaza that a group of Hamas fighters had ambushed an Israeli undercover unit operating near Netzarim, beginning the day's clashes.
The Israeli army said it had no information about any ambush. Earlier Saturday, the army said Palestinians had fired two anti-tank missiles and sprayed machine gun fire at Israeli soldiers near Netzarim, but that nobody had been injured.
Later, Palestinian medical sources said a medical worker had been shot in the stomach and wounded.
Meanwhile, Palestinians sought European backing Saturday for U.N. enforcement of a nonbinding international court ruling that found Israel's massive West Bank barrier to be illegal, even as Israel enlisted American support.
In the Gaza Strip, residents said Israel tightened a security crackdown now in its 12th day, leaving them short of water, milk and other essentials. The operation, aimed at stopping rocket attacks, began after a June 28 strike in the Israeli town Sderot killed two people, including a 3-year-old.
Israeli Foreign Minister Silvan Shalom, speaking to Israel radio, said he has asked U.S. officials to prevent the adoption of any U.N. resolution aimed at enforcing the court's decision.
The Palestinians have said they will seek the support of the world body's members in the General Assembly, then go to the Security Council.
"The issue will go to the Security Council because the (Palestinians) have an automatic majority in the U.N. General Assembly," Shalom said.
Palestinian Prime Minister Ahmed Qureia told European envoy Marc Otte that the Palestinians want Europe's support at the United Nations.
Qureia told Otte he hoped the Americans would not "sabotage our efforts," according to participants in the meeting. Washington has veto power in the Security Council and often has blocked proposed resolutions it found to be no in Israel's interests.
"Now, it is the responsibility of the international community, it is the responsibility of the U.N., to put (in place) a mechanism to commit Israel to this decision," Qureia told reporters after the meeting.
Otte, standing by his side, was noncommittal, though he noted past EU objections to the barrier.
"We have to look carefully at what the court says and what the consequences are," Otte said. As to the General Assembly, "we have to see how things happen."
Several European countries had supported the Israeli and U.S. position that the world court should not interfere on the barrier because the issue was political, not legal, and could disrupt Mideast peace efforts. The court, however, rejected that argument, saying it had jurisdiction to give an advisory opinion.
Washington said its position hasn't changed.
"It remains our view that this referral to the court was inappropriate and that, in fact, it could impede efforts to achieve progress toward a negotiated settlement between Israelis and Palestinians," State Department spokesman Richard Boucher said.
Washington, he said, also rejects the idea there should be "further action" by the United Nations in light of the court ruling.
In its advisory ruling Friday, the U.N.'s International Court of Justice in the Hague, Netherlands, declared the barrier illegal and said construction must stop. It urged the General Assembly and Security Council to consider "what further action is required to bring to an end the illegal situation."
Israeli officials declared it was their right and duty to protect "innocent citizens" with the barrier, which they say has vastly reduced militant attacks against Israelis. Construction was continuing on the 425-mile barrier of high concrete walls, razor-wire fences, trenches and watch towers.
Israeli Prime Minister Ariel Sharon and his government planned to meet Sunday with the attorney general to discuss implications of the court's opinion.
Palestinian leader Yasser Arafat, in a speech congratulating graduates of a security training program, called Friday's decision by the International Court of Justice "a pronunciation from the world it is standing beside the Palestinian people against the apartheid wall."
In the Arab world, the court's decision was welcomed, but the leader of Lebanon's Hezbollah guerrilla group said the U.S. would block any Security Council attempt to force the barrier's removal. "Americans will be waiting there with a ready veto," Sheik Hassan Nasrallah said.
A teenaged girl was killed Saturday in Gaza and, separately, three women were injured and pinned down under Israeli gunfire that kept residents from helping them, according to Palestinian residents and medical workers. They were hospitalized later, two with moderate injuries and one critically hurt, Palestinian doctors said.
The Israeli army said one woman was injured in the Beit Hanoun incident, apparently by a ricocheted bullet after soldiers fired warning shots over a group of Palestinians that soldiers felt were a threat. Ambulances entered quickly, it said.
The army had no information on the death of a teenager in Rafah, near the border with Egypt, who Palestinian medical sources identified as Hanen Abu Samhdana, 16.
In recent days, Palestinians say the army has tightened its siege on Beit Hanoun, closing smaller roads into town, knocking out water and electricity and placing snipers on rooftops. Bulldozers have uprooted orange and olive trees, according to residents, replacing them with army camps.