JERUSALEM (AP) — A Palestinian attacker opened fire early Tuesday at the entrance to a settlement outside Jerusalem, killing three Israeli security men and critically wounding a fourth, Israeli police and medical services said, in one of the deadliest attacks in a two-year spate of violence.

Gaza's Islamic Hamas rulers praised the attack but stopped short of taking responsibility for it. Israeli officials said the attacker was a 37-year-old father of four who appeared to have acted alone.

The attack comes at a tense period amid the Jewish high holidays and is likely to complicate the mediation efforts of U.S. peace envoy Jason Greenblatt who had just arrived in the region for meetings with Israeli and Palestinians leaders.

Police spokeswoman Luba Samri said the attacker approached the back gate entrance of the Har Adar settlement, hiding among dozens of Palestinian day laborers who were being checked by security forces.

The man aroused police suspicions and was asked to stop, Samri said. At that point, he pulled out a weapon and began opening fire from a short distance. The attacker, who held a valid permit to work in Israel, was then shot dead by other forces at the scene.

The Magen David Adom medical service said that in addition to the three killed, a fourth Israeli man, 32, was evacuated to hospital in critical condition. The casualties were identified as Solomon Gavria, a 20-year-old policeman, and two private security guards.

Har Adar is an upscale community west of Jerusalem, straddling the seam line between the West Bank and Israel proper — and an unusual target in the wave of violence that Israel has been coping with over the past two years.

Shay Retter, the head of Har Adar's security committee, said that between 100 and 150 Palestinian laborers typically enter the community each day for work. Local residents said they knew the attacker from previous work he had carried out in the community and were shocked to hear what he had done. The military imposed a closure on the nearby Palestinian village of Beit Surik, the home of the attacker.

Israeli Defense Minister Avigdor Lieberman blamed Tuesday's assault on incitement he said was encouraged by the Palestinian leadership, adding that he sees no difference between Palestinian terrorism and radical Islamic terrorism targeting sites in Europe and elsewhere.

"Before talking about any kind of negotiations, the world must demand of the Palestinian Authority to stop its incitement and encouragement of terror," he said.

Since September 2015, Palestinians have killed 51 Israelis, two visiting Americans and a British tourist in stabbings, shooting and car-ramming attacks.

During that same time, Israeli forces have killed over 255 Palestinians. Israel says most of them were attackers and others died in clashes with Israeli forces. Most of the attacks have been stabbings against security forces, primarily in the West Bank.

Israel blames the violence on incitement by Palestinian religious and political leaders compounded on social media sites that glorify violence and encourage attacks. Palestinians say the attacks stem from anger and frustration at decades of Israeli rule in territories they claim for a state.

The frequency and intensity of attacks has lessened of late but such an incident, coming amid the Jewish high holiday, threatened to ignite them anew.

Gaza's Hamas rulers called Tuesday's assault a "heroic operation" that was a "natural response" to Israeli aggression against Palestinians and proved that the Palestinian uprising was still alive.

Israeli President Reuven Rivlin said "the cruel terror attack proves once again the daily front that our security forces face in the most important mission — protecting and defending the safety of the citizens of Israel."

Israel's Cabinet was to convene later in the day for a previously scheduled meeting.