Updated

Israel clamped long-term travel restrictions on West Bank Palestinians Monday, barring them from major roads amid fears that two drive-by shootings signaled the start of a new round of Palestinian attacks against Israelis in the territory.

The shootings, the restrictions and Israel's suspension of talks with the Palestinian Authority (search) deflated hopes that Israel's pullout from the Gaza Strip and months of relative calm would create a new tings. "These events harm the cease-fire and the calm that we have respected," he said.

The effects of the new restrictions were immediately felt across the West Bank, where dozens of new checkpoints appeared on major roads overnight and Palestinian drivers were forced onto smaller back roads.

Israel had restricted Palestinians from traveling on the main roads during much of the Palestinian uprising but started letting them back after a truce agreement was reached in February.

Israeli security officials said the government planned to force Palestinian drivers onto separate roads in the West Bank next year after enough bridges and tunnels were built to give them freedom of movement. The attacks Sunday spurred Israel to enforce the plan immediately, said the officials, speaking on condition of anonymity because they are not authorized to talk to the media.

Palestinian emergency vehicles would still be allowed to use the roads, Israel said.

Israel also sealed off the West Bank (search) towns of Hebron and Bethlehem and said it would step up arrest raids against militants. Soldiers arrested 19 wanted Palestinians in the West Bank overnight, the army said.

Palestinian officials said the restrictions would only worsen the Palestinians' already high poverty and unemployment levels.

Israel also suspended talks with the Palestinian Authority on prisoner releases and arrangements for the Gaza-Egypt border, Israeli Foreign Ministry spokesman Mark Regev said. Other contacts, such as security meetings between local commanders, were not affected.

"In Israel, we have no desire to return to a reality of daily attacks against Israeli civilians," Regev said. "We want to send a very strong and sharp message to the Palestinians, and the temporary suspension of talks is that message."

Abbas said he believed the suspension would be brief.

"We are totally certain that they are going to start again very quickly," he said.

Months of reduced violence and Israel's unilateral Gaza pullout increased international hopes for renewed peace moves. As a first step toward talks, however, Israel demanded Abbas dismantle the militant groups, a move he refused.

The violence was likely to increase pressure on Abbas, who is to meet later this week with President Bush, to confront the militants.

"The Palestinian Authority has to move from the talking stage to the action stage," Israeli Defense Minister Shaul Mofaz said. "We will not be able to continue in this process if the Palestinian Authority does not start taking concrete actions against the terror groups."

After its Gaza pullout last month, Israel received intelligence warnings that militants would shift their focus to the West Bank.

The violence Sunday marked the bloodiest attacks against Israelis in more than three months.

In the first assault, militants in a car shot up a bus stop at the Gush Etzion junction in the West Bank, killing three people. One Israeli was seriously wounded in the second attack near the settlement of Eli.

The Al Aqsa Martyrs' Brigades, a militant group with ties to Abbas' Fatah party (search), claimed responsibility. However, Kamel Ghanam, an Al-Aqsa leader in Ramallah, said his group was not behind the attack, and Israeli security officials said they believed the Islamic militant group Hamas was involved.

On Monday, hundreds of settlers stood silently at the Gush Etzion junction before a 3-foot tall pile of memorial stones covered by Israeli flags. Some mourners quietly cried. Many said they had feared an attack like this was coming.

"Once you loosen up security measures to make life easier, unfortunately, terrorists take advantage of it," said Menachem Leibtag, 51, of the nearby settlement of Alon Shvut.

Liebtag said Palestinian moderates had a duty to rein in militants: "If they are not going to stop the terror, they can't drive on our roads."

On the road between Gush Etzion and Hebron to the south, soldiers set up new checkpoints Monday complete with spiked strips to force vehicles to stop. Soldiers waved back a taxi van with a green Palestinian license plate, while letting cars with yellow Israeli plates pass.

Palestinian pedestrians also were stopped and searched at checkpoints before being allowed to cross the main road running north-south through the West Bank.