The Israeli government suspended contacts with the Palestinian Authority and imposed travel restrictions on the West Bank today after gunmen killed three people in two drive-by shootings.
Five people were wounded in the attack near the Gush Etzion block of Jewish settlements yesterday, which was the deadliest since July.
It followed Israeli intelligence warnings that Palestinian militants, who claim they drove Israel out of Gaza by force, would now shift their focus to the West Bank.
Last month Jewish settlers were forced out of their homes in Gaza and four West Bank communities under Israel's disengagement plan.
The Al Aqsa Martyrs' Brigades, a militant group with ties to the ruling Fatah party, claimed responsibility for yesterday's attacks. However, security officials said they believed Hamas might have been involved.
Palestinian negotiator Saeb Erekat said the shootings were "unfortunate" and accused the gunmen of trying to sabotage efforts to revive peace talks. He urged Israel to reconsider the travel restrictions and suspension of contacts, saying "angry messages, collective punishment and violence will just add to the complexities".
Mr Erekat said Israeli negotiators failed to show up for a meeting last night on the reopening of the Rafah terminal on the Gaza-Egypt border. The opening of the crossing is crucial to the economic recovery of Gaza.
Israeli foreign ministry spokesman Mark Regev initially said all contacts with the Palestinian Authority had been suspended, but later said it applied only to committees on specific issues such as prisoner releases, security and customs at border crossings.
"In Israel, we have no desire to return to a reality of daily attacks against Israeli civilians," he said. "We want to send a very strong and sharp message to the Palestinians, and the temporary suspension of talks is that message."
In the first attack, militants in a car opened fire on Israelis waiting at a bus stop and at others in nearby vehicles. A 15-year-old boy and two of his cousins in their 20s were killed. The second attack took place near the settlement of Eli in the northern area of the West Bank.
Israeli authorities responded by limiting movement in the West Bank, security officials said. The West Bank towns of Hebron and Bethlehem, close to Gush Etzion, were sealed off, and Palestinian-owned cars were barred from the West Bank's main north-south road.
Israel says the Palestinians must dismantle militant groups if they want to restart peace talks.