The Israeli government moved swiftly Monday to assert greater control over the West Bank, a day after Palestinian gunmen killed three young Israelis and wounded several others in a pair of drive-by shootings. Officials on both sides warned of a general escalation in the conflict.

Early Monday, Israeli Defense Minister Shaul Mofaz banned private Palestinian cars from major West Bank roads and cut contacts between the Israel Defense Forces and the Palestinian security services. Israeli forces largely sealed off the cities of Bethlehem and Hebron.

The Israeli government also suspended several Israeli-Palestinian negotiating committees that were revived earlier this month to study the release of Palestinian prisoners, the status of Palestinian fugitives and further Israeli military withdrawals from the West Bank. Israel pledged in February to leave the territory's largest cities.

"We want to send a very clear and unequivocal message that after attacks like this it's not business as usual," said Mark Regev, a spokesman for the Israeli Foreign Ministry, who stressed that the Israeli steps were temporary. "We expect them to follow through on their promises -- that these armed gangs be disarmed. Our entire ability to move forward is based on that promise."

Since the Israelis completed their withdrawal from the Gaza Strip in August, Israeli and Palestinian leaders have pledged to work toward reviving the U.S.-backed peace plan known as the "road map," which aims at the ultimate creation of a Palestinian state.

Palestinian officials warned Monday that momentum created by the Gaza evacuation was fading quickly. "This response is the way toward escalation," said Saeb Erekat, the chief Palestinian negotiator. "In the past, such Israeli measures have been only the first step toward more violence."

Israeli military forces moved overnight to reestablish a network of roadblocks and checkpoints in the West Bank, which has been occupied by Israel since the 1967 Middle East War. Some of those barriers had been removed after Palestinian leader Mahmoud Abbas formalized a temporary cease-fire in March.

On Monday, concrete blocks sealed off towns along the highway running south from Jerusalem to Hebron. On this road, at a junction popular with hitchhikers, Meitat Rosenfeld-Adler, 23, Kinneret Mandel, 24, and Oz Ben Meir, 15, were shot dead Sunday afternoon. The victims, all of them Jewish settlers, were buried Monday in Jerusalem and the West Bank. A small stone shrine draped in Israeli flags was quickly placed at the site of the shooting.

The new barriers sent collective taxis and public buses on long back-road treks that turned daily commutes into half-day journeys for many Palestinians.

Here in El-Khader, a hillside village of olive groves and a stone church commemorating the site of Saint George's family home, the barriers kept out vehicles. A line of men and women, trudging with shopping bags and swaddled infants, was forced to hike more than a mile to catch the nearest public transportation.

Haytham Manassra, 29, worked Sunday in Hebron, about 15 miles south of here. But when he tried to return home Sunday afternoon, the Israeli military had closed the roads. After spending the night in Hebron, he left his Hyundai there Monday morning because a ban was announced on private cars. Four taxi rides, several lengthy hikes through dry riverbeds and four hours later he arrived at El-Khader -- a trip that normally takes him about 25 minutes.

"Those who suffer are the civilians," said Manassra, a Palestinian salesman for Israel's leading ice cream company. "If the situation stays this way, I'll have to remain at home tomorrow."

The al-Aqsa Martyrs Brigades, the armed wing of the ruling Fatah movement, asserted in a statement Monday that the attacks were a response to the killing of an al-Aqsa fighter in Jenin two weeks ago by the Israeli military. The group has put Abbas, the head of Fatah, in an awkward position as he heads into a meeting on Thursday with President Bush in Washington.

"Israel took unilateral measures, such as the removal of roadblocks to ease up on the Palestinian population, and typically the al-Aqsa Brigades exploited this to kill Israeli civilians," said Dore Gold, an adviser to Prime Minister Ariel Sharon. "This raises the question of whether Israel should be expected to do so in the future in the absence of Palestinian security measures."

Abbas is facing pressure from Sharon and the Bush administration to disarm the Palestinian militias, particularly the military wing of the radical Islamic faction Hamas. But he has made little progress at a time when Hamas, formally known as the Islamic Resistance Movement, is benefiting politically from claims that its attacks forced Israel from Gaza after more than a decade of Fatah-backed negotiations failed to do so.

The parties are now feuding over the timing of elections.

Palestinian election officials said Monday that the Palestinian Authority, dominated by Fatah, decided last week to hold the final round of municipal elections on Dec. 15 in major West Bank cities and in three small communities in Gaza. But the authority postponed voting in Gaza City and other urban areas in the strip, all Hamas strongholds. Hamas condemned the decision on its Web site, calling it "a violation of the will of the Palestinian people for reform."

A mourner in Jerusalem cries during the funeral for two of the three young Jewish settlers killed Sunday in a drive-by attack by Palestinian gunmen.