A Palestinian wielding a knife stabbed and killed three Israelis in Halamish, a settlement located north of Ramallah. A fourth Israeli was wounded in the attack, the Israeli MDA emergency services told CNN.
MDA Director Eli Bin said the attacker was shot and severely wounded, and has also been evacuated to hospital. The Israeli military confirmed in a statement that the assailant had been shot.
In a statement posted on Facebook prior to the attack, the assailant said he was motivated by the Israeli government's recent restrictions on al-Aqsa mosque in Jerusalem, according to an Israeli military spokesman. The attacker climbed a fence and "was able to penetrate one of the houses, which was close to the village perimeter," said the spokesman, who did not want to be named.
Palestinian militant group Hamas praised the attack. "We bless the heroic Halamish operation which came as a result to the Zionist occupation violations and crimes against our people in Jerusalem and al-Aqsa Mosque," the group said on Twitter.
Earlier on Friday, three Palestinians were killed in clashes with Israeli forces in Jerusalem's Old City, Palestinian officials said.
More than 100 other Palestinians were injured in the clashes in east Jerusalem neighborhoods, according to Rafiq El Husseini, director of Al Maqassed Hospital, where bodies of two of the dead were taken.
United Nations Secretary-General António Guterres issued statements condemning both episodes of violence. He called "on all to refrain from any actions or words that could further escalate an already volatile situation."
Tensions were fueled by a decision by Israeli authorities to install metal detectors at entrances to a key Muslim holy site in the Old City and bar male worshipers under 50 from attending Friday prayers there.
The restrictions were imposed after two Israeli police officers were killed in a shooting
last week just outside the Old City and Temple Mount, also known as the Noble Sanctuary. The area is one of the world's most important religious sites, revered by Jews, Christians and Muslims.
Palestinian President Mahmoud Abbas on Friday suspended all contacts with Israel until the metal detectors are removed.
"I announce the freezing of contacts with Israel on all levels and the suspension of coordination until all the measures taken at al-Aqsa mosque have stopped," Abbas said in a message tweeted by his Fatah Movement.
Israeli police told CNN they were aware of reports that two people had been taken to hospital and that one had died, but said they could not comment officially as they were still investigating the incident.
Police are also investigating reports that Israeli police entered the hospital looking for the body of a dead Palestinian, police foreign press spokesman Micky Rosenfeld told CNN.
Mohammad Fityani, a spokesman for the Palestinian Red Crescent in Jerusalem, told CNN that its crews had dealt with 109 injured people by 3 p.m. local time, 72 of whom had been taken to the hospital. Three of those were seriously hurt and one later died, he said.
Tensions in Jerusalem's Old City boiled over into skirmishes after the midday prayer.
In one instance, a CNN team outside Herod's Gate saw Israeli police start forcefully pushing worshipers back and pointing their weapons at them. The officers then fired rubber bullets and stun grenades to disperse the worshipers and move them back.
The Waqf, the Jordanian religious authority that administers the Temple Mount, has condemned the use of metal detectors to scan worshipers. Waqf religious leaders have refused to enter through the detectors which have been set up as part of the security clampdown.
Israeli police said they were working to ensure that Friday prayers were able to continue while the heightened security measures are in place.
Israeli Prime Minister Benjamin Netanyahu has said the metal detectors do not signal changes in the way the Temple Mount/Noble Sanctuary is run. "There is absolutely no change to the status quo," he told reporters earlier in the week.
The Temple Mount/Noble Sanctuary was closed after last Friday's attack, and reopened Sunday for worshipers, visitors and tourists, with added security measures.
It is home to the Western Wall -- which was part of the walls around the Second Jewish Temple and is one of the holiest places for Jews to pray -- and the Dome of the Rock, where Muslims believe the Prophet Mohammed ascended to heaven.