JERUSALEM, Aug. 4 - An Israeli Army deserter dressed in a military uniform opened fire on Thursday aboard a bus carrying Israeli Arab passengers in northern Israel. Four were killed and at least a dozen wounded before an angry crowd beat the gunman to death, according to Israeli authorities and witnesses.
The shooting was one of the deadliest by a Jewish attacker in recent years and appeared to be an attempt to start an upheaval to sabotage Israel's planned evacuation of Jewish settlers from the Gaza Strip and part of the West Bank, which is set to begin on Aug. 15. Israeli security services have repeatedly expressed concerns about such a possibility.
The gunman was identified by the military as Eden Natan Zada, 19, though it initially identified him as Eden Tzuberi. He was an army private who was reported absent without leave around mid-June after refusing to take part in preparations for the Gaza pullout.
According to his family and Israeli news media reports, Mr. Zada then went to live in Tapuah, one of the most militant Jewish settlements in the West Bank.
Prime Minister Ariel Sharon called the shootings "a reprehensible act by a bloodthirsty Jewish terrorist who sought to attack innocent Israeli citizens."
Gideon Ezra, Israel's minister for public security, has spoken in favor of detaining Jewish militants without charges before the Gaza withdrawal, saying it could prevent violence.
The shooting on Thursday is certain to inflame passions on all sides.
"We are witnessing attempts by extreme right-wing people, terrorists, who want to set the region ablaze and feel they have freedom of action," Muhammad Barakeh, an Arab member of Israel's Parliament, was quoted as saying on the Web site of the newspaper Haaretz.
He and the news media said Mr. Zada had been a supporter of the Kach movement, founded by Rabbi Meir Kahane, the anti-Arab militant who was assassinated in New York in 1990. While the movement is outlawed in Israel, many Tapuah residents are believed to be supporters.
Mr. Zada grew up in Rishon Lezion, in central Israel, but went to Tapuah after leaving the army.
Settler leaders contended that he was not a resident. But his father, Yitzhak, said that his son had been living in Tapuah and that he had informed army officials of his son's whereabouts and told them to repossess his weapon.
"I wasn't afraid that he would do something," he told The Associated Press. "I was afraid of the others" in Tapuah. He said he spoke to his son two days ago, "and he told me he would find the time to return the weapon." The Israeli military said it was investigating why he still had his weapon after he had deserted.
Mr. Zada, who was wearing a skullcap that identified him as an Orthodox Jew, apparently boarded the bus in the northern Israeli city of Haifa and waited until it reached Shefaram, an Arab town several miles to the east, witnesses said.
When the bus reached the town, the driver asked to speak to Mr. Zada, inquiring whether he had intended to come to the town, said Avtihaj Salameh, a passenger quoted by Haaretz. He stood by the driver for several minutes, then opened fire, Mr. Salameh said.
A large crowd then charged the bus and attacked Mr. Zada, beating him to death, witnesses and the news media reported.
Israeli television showed video of bodies on the side of the road, covered in sheets, and the broken windows of the bus.
Jewish militants have carried out a number of attacks against Arabs in the past, but most were directed against Palestinians in the West Bank rather than Arabs who are Israeli citizens. In the deadliest such attack, Baruch Goldstein, an American-born settler in the West Bank, shot dead 29 Muslim worshipers in 1994 at the Tomb of the Patriarchs, a site in Hebron that is holy to Muslims, Jews and Christians.
Issam Makhoul, an Arab member of Israel's Parliament, said Israeli political leaders had "been questioning the legitimacy of our citizenship in the past few years, and today someone took the initiative and acted on this."
Israeli Arabs, who constitute more than 1 million of Israel's 6.8 million citizens, have generally not been directly involved in the violence of the past few years, though a number have been implicated in assisting Palestinian attackers coming to Israel from the West Bank.
As the Gaza pullout approaches, right-wing Israelis have been holding protests, though the latest effort fizzled on Thursday.
Gaza has been declared off limits to nonresidents, but some protesters said they had managed to sneak into the Gaza settlements in recent days.
Bentzi Lieberman, the head of the main settler organization, the Yesha Council, condemned Thursday's shooting. "Murder is murder is murder, and there can be no other response but to denounce it completely and express revulsion," he said.
Earlier on Thursday, an estimated 10,000 Palestinians rallied outside their Parliament building in Gaza City to celebrate the planned Israeli withdrawal. "After 38 years of ugly occupation, they are leaving and they will never come back," the Palestinian prime minister, Ahmed Qurei, said of the Israelis.