Seven people were dead after a perpetrator carried out an armed attack in occupied East Jerusalem on Friday, police said.
Police said several others were injured in the attack on a synagogue. Rescue services said some of these were in critical condition.
The attacker was "neutralized," police said.
Police originally put the number of fatalities at eight. Several others were injured, the police said on Twitter.
The attacker went to a synagogue in the illegal settlement of Neve Yaakov at around 8:30 p.m. (6:30 p.m. GMT) and opened fire, according to police.
The security situation in Israel and Palestine has worsened sharply in the past few days.
A spokesperson for the Hamas movement, which rules the Gaza Strip, said Friday's attack was in retaliation for an Israeli army raid on the Jenin refugee camp in the West Bank on Thursday.
Nine Palestinians, including an elderly woman, were killed and 20 others injured in an Israeli raid in Jenin.
The Palestinian Health Ministry accused Israeli forces of deliberately firing tear gas inside a hospital's pediatric ward, leaving children choking – a claim denied by an Israeli army spokesperson who added that gas may have drifted into the clinic through a window.
The bloodiest day in the West Bank in years erupted during a raid on the crowded refugee camp in the northern city of Jenin, where gunshots rang through the streets and smoke billowed from burning street barricades.
The Palestinian Health Ministry said the death toll from the clashes rose to "nine martyrs" including a woman, and that 20 people were wounded before the Israeli forces withdrew midmorning.
In Gaza, Hamas spokesperson Hazem Qassem told Reuters: "This operation is a response to the crime conducted by the occupation in Jenin and a natural response to the occupation's criminal actions," though he stopped short of claiming the attack.
The United States quickly condemned the attack.
"This is absolutely horrific," State Department spokesperson Vedant Patel told reporters.
"We condemn this apparent terrorist attack in the strongest terms. Our commitment to Israel's security remains ironclad, and we are in direct touch with our Israeli partners."
"We stand with the Israeli people in solidarity," he said.
Patel told reporters at a news briefing that U.S. officials were in touch with their Israeli counterparts and that he did not expect changes to Secretary of State Antony Blinken's vist to Israel next week.
U.S. President Joe Biden directed his national security team to offer support to their Israeli counterparts.
U.N. Secretary-General Antonio Guterres also condemned the attack.
"The Secretary-General strongly condemns today's terrorist attack," his spokesman said. "It is particularly abhorrent that the attack occurred at a place of worship, and on the very day we commemorated International Holocaust Remembrance Day."
However, he urged the sides to exercise the "utmost restraint." Guterres is "deeply worried" by the current escalation of violence in Israel and the occupied Palestinian territory, U.N. spokesperson Stephane Dujarric said in a statement.
The United Arab Emirates (UAE) also condemned Friday’s synagogue attack on the outskirts of East Jerusalem, state news agency (WAM) reported citing a foreign ministry statement.
Britain's foreign secretary, James Cleverly, also condemned the attack. "To attack worshippers at a synagogue on Holocaust Memorial Day, and during Shabbat, is horrific. We stand with our Israeli friends," he said in a statement on Twitter.
Türkiye also condemned the attack and called on all sides to take steps to prevent any further violence.
The surging violence comes a month after a new government, led by veteran Prime Minister Benjamin Netanyahu, took power.
Netanyahu and his extreme-right National Security Minister Itamar Ben-Gvir visited the scene on Friday, as crowds chanted "death to Arabs," Agence France-Presse (AFP) journalists at the scene said.
Speaking on television after visiting the scene, Netanyahu said his Security Cabinet would soon announce "immediate measures" in response and urged Israelis not to "take the law into their own hands."
Meanwhile, Israeli Defence Minister Yoav Gallant, who was on a family visit to the U.S., has cut short his trip and is returning to Israel, his office told AFP.
"The attack against civilians this Friday evening was horrific," Gallant said in a statement, vowing to "operate decisively and forcefully against terror and will reach anyone involved in the attack."
