JERUSALEM – A Jewish settler absent without leave from the Israeli army opened fire yesterday on a public bus traveling to an Arab town in northern Israel, killing at least four people and wounding 10. In the immediate aftermath, passengers swarmed the gunman, killing him before he could leave the bus.

In a statement, Prime Minister Sharon called the shooting “a reprehensible act by a bloodthirsty Jewish terrorist who sought to attack innocent Israeli citizens.” Israeli police officials suggested it was an attempt to derail the government’s planned evacuation of Jewish settlements in the Gaza Strip and four in the West Bank, scheduled to begin later this month. The gunman, identified as Eden Natan Zada, 19, had recently moved to a West Bank settlement known as a stronghold of religious extremists opposed to the evacuation plan, Israeli police officials said.

Witnesses said Zada, wearing the skullcap and thick beard of religiously observant Jews, boarded the Egged Bus no. 165 from Haifa wearing an Israeli army uniform. Jewish and Arab residents of Israel’s Lower Galilee regularly ride the route, which passes through the Jewish community of Kiryat Ata before ending in the Arab town of Shfaram.

Ibtihaj Salame, 57, got on the bus at Kiryat Ata, usually the last stop for its Jewish passengers. An ethnic Druze woman with three sons in the Israeli military, Ms. Salame was returning home from a medical appointment in Haifa. She said she usually avoids buses for fear of suicide bombers but was forced to take one yesterday after missing her shared taxi.

In a telephone interview a few hours after the 5:30 p.m. shooting, she said she took a seat in front of a man dressed in an army uniform. Ms. Salame said the bus driver asked the soldier to move to the front of the bus, but she said he refused. She got off the bus at the second stop inside Shfaram, a town of 34,000 people about 65 miles north of Jerusalem, and heard shots ring out from inside the bus as she did.

“No one spoke to him on the bus other than the driver,” Ms. Salame said. “No one thought or imagined that he was up to something. But maybe the driver did.”

The driver, who was slain, was identified as Michel Bahoud, 55, an Arab Christian from the Lower Galilee region. Two of the other victims were women, one a Christian and one a Muslim. The fourth victim was a Muslim man. Police said all four were Israeli Arabs.

The event recalled the 1994 attack carried out by Baruch Goldstein, who gunned down 29 Palestinian Arabs in a mosque at the Tomb of the Patriarchs in the West Bank city of Hebron. Goldstein, who was also dressed in an army uniform, was killed before he could leave the mosque. The shooting marked the beginning of a difficult period for the Oslo accords between Israel and the Palestinians signed the previous year.

In his statement, Mr. Sharon called yesterday’s attack “a terrorist event” and said it was “a deliberate attempt to harm the fabric of relations among all Israeli citizens. Terrorism by civilians against civilians is the most dangerous thing affecting the future of the state of Israel and its stability as a democracy.”

The attack also was condemned by leaders of the umbrella organizations of Jewish settlements in the West Bank and Gaza, the Yesha Council. The organization has staged large demonstrations against the disengagement plan, which Mr. Sharon has said is needed to ensure Israel’s security and the long-term viability of its Jewish majority.

“We think there is no connection between this and our movement,” the council’s deputy chairman, Shaul Goldstein, said. “He’s a terrorist, a lunatic, and immoral. He has no connection to my values. He’s a criminal and should be treated like one.”

Israeli police officials said Zada, the son of secular Jewish parents, had moved recently to the West Bank settlement of Tapuah. Many of the community’s roughly 600 residents are followers of the late Meir Kahane, who favored the expulsion of Arabs from Israel and the land it occupied in the 1967 war. Many settlers believe the land was promised to the Jewish people by God.

A Jewish religious academy, or yeshiva, in the settlement was founded by Kahane’s followers. The religious-political movement he inspired, known as Kach, is designated as a terrorist organization by the State Department.

Israeli military officials said Zada, originally from the Israeli town of Rishon Letzion, had been absent from his unit in southern Israel since June 14 in apparent protest against the Gaza evacuation. He joined the army in January and was still undergoing basic training.

In a letter he left at his base, Zada wrote that he “could not be part of an organization that expels Jews,” according to copy published yesterday evening on the Israeli news Web site Ynet.

Nakad Nakad, 40, witnessed the shooting from the balcony of his home in the center of Shfaram. He said he heard shots from inside the bus, then watched as rifle fire sprayed from the windows into the street around it.

“It is clear he intended to kill Arabs inside Shfaram, to have a massacre,” Mr. Nakad, a political leader of a community movement, the Democratic Front for Peace and Equality, said. “That’s why he waited for the bus to get inside the town.”