Israel denied entry permits for 83,000 Palestinians and sent hundreds of soldiers into the occupied West Bank on Thursday, in response to a shooting attack by Palestinian gunmen that killed four Israelis in Tel Aviv the previous day.
No group has claimed responsibility yet for the attack, which was carried out by two Palestinian assailants who opened fire in a shopping and dining market, but Hamas and other Palestinian militant groups were quick to praise it.
The assailants came from near Hebron, in the Israeli-occupied West Bank. They dressed in suits and ties and posed as customers at a restaurant before pulling out automatic weapons and opening fire, sending diners fleeing in panic.
The dead included two women and two men, while six people were wounded. The attack followed a lull in recent weeks after what had been near-daily stabbings and shootings on Israeli streets. It was the deadliest incident in eight months.
The attackers, cousins in their 20s who security experts said appeared to have entered Israel without permits, were quickly apprehended. One of them was shot and wounded.
"They got some support, although we don't know for sure who their supporters are," Barak Ben-Zur, former head of research at Israel's Shin Bet domestic security agency, told reporters. He added that they appeared to have used improvised automatic weapons smuggled into Israel.
The attack took place just a couple of hundred yards from the fortified Defense Ministry in the heart of Tel Aviv, which has seen far less violence than Jerusalem.
Israel's military said it was revoking some 83,000 permits issued to Palestinians from the West Bank to visit relatives in Israel during the ongoing Muslim holy month of Ramadan. The restrictions prevent thousands of Palestinians from praying at Jerusalem's Al Aqsa mosque during the holiday.
Israel also announced that two battalions would be deployed in the West Bank by the end of the day to reinforce troops stationed in the area, where the military maintains a network of checkpoints and often carries out raids to arrest suspected militants. Israeli battalions are comprised of around 300 troops.
Such collective punishment measures, including restrictions on access to Jerusalem's Aqsa Mosque compound, the holy site in the heart of the Old City that Jews refer to as Temple Mount, have in the past lead to increased tension with the Palestinians.
After Wednesday's attack, fireworks were set off in parts of the West Bank and in some refugee camps people sang, chanted and waved flags in celebration, locals said.
Hamas spokesman Hussam Badran called it "the first prophecy of Ramadan" and said the location of the attack, across the road from Israel's fortified Defence Ministry, "indicated the failure of all measures by the occupation" to end the uprising.
During the recent wave of violence, Israel's government has repeatedly criticized Palestinian factions for inciting attacks or not doing enough to quell them.
The Popular Front for the Liberation of Palestine, the largest group in the Palestine Liberation Organization after Fatah, the Western-backed party of President Mahmoud Abbas, described the killings as "a natural response to field executions conducted by the Zionist occupation".
The group called it a challenge to Avigdor Lieberman, Israel's new defense minister, who must decide how to respond to the violence, possibly with tighter security across the West Bank. Lieberman said he would act, but didn't say how.
The United Nations' special coordinator for the Middle East, Nickolay Mladenov, condemned the shootings and expressed alarm at the failure of Palestinian groups to speak out against the violence. The European Union did the same.
Netanyahu visited the scene minutes after arriving back from a two-day visit to Moscow. He described the attacks as "cold-blooded murder" and vowed retaliation.
"We will locate anyone who cooperated with this attack and we will act firmly and intelligently to fight terrorism," Netanyahu said.
A first step was to shut down the area around Yatta and suspend work permits held by 204 relatives of the attackers.
Since October last year, 32 Israelis and two visiting US citizens have been killed by Palestinians. Israeli forces have shot dead at least 196 Palestinians, 134 of whom Israel has said were assailants. Others were killed in clashes and protests.