Human Rights Voices

Two Palestinians attacked a synagogue in Jerusalem, killing three American-Israeli rabbis, a British-Israeli rabbi and a policeman and shifting the focus of violence to deep within the heart of the Jewish half of the city.

It was the deadliest attack on Israelis in Jerusalem in six years.

The assailants, armed with a rifle and butcher knives, targeted the Kehilat Bnei Torah synagogue in the ultra-Orthodox Jewish neighborhood of Har Nof on Tuesday. The area is far from the line that divides Jerusalem's Arab and Jewish halves, which has been the focus of a raft of other attacks since July. Police said they traded gunfire with the attackers for several minutes before killing them.

The scale and the targeting of worshipers in a synagogue rattled Israelis more deeply than any other attacks recently in the city. Jerusalem has been roiled by unrest for more than four months, fanned by a feud over the city's most sensitive holy site, the Temple Mount.

The two attackers entered the synagogue at about 7 a.m. as some 30 people were praying, and began stabbing worshipers before opening fire, the foreign ministry said. As witnesses entered the synagogue, they found worshipers dead, wrapped in prayer shawls sprawled on the floor in pools of blood.

"I felt like I was in a butcher shop," said Albert Albukai, a medic who heard the gunshots while praying at a neighboring synagogue. He said he saw worshipers who had been stabbed in their necks.

"They were all slaughtered; at least four were dead. We could do nothing for them."

Israeli and Western leaders and Palestinian President Mahmoud Abbas condemned the attack.

"There is and can be no justification for such attacks against innocent civilians," President Barack Obama said.

It wasn't immediately clear whether the attackers acted alone or on behalf of an organization.

The Popular Front for the Liberation of Palestine, an armed faction that is smaller but more radical than the Islamist group Hamas, said the attackers were members, but stopped short of claiming responsibility. Israel police said they believed they acted alone. The daily Haaretz quoted Yoram Cohen, the chief of Israel's Shin Bet intelligence service, telling lawmakers that the attackers had no previous links to militant groups.

Hamas, which rules the Gaza Strip, praised the attack and said it was a response to "continued Israeli crimes, the killing, desecrating Al Aqsa," a reference to the mosque which sits atop the Temple Mount.

Israeli Prime Minister Benjamin Netanyahu blamed Hamas but also accused the more moderate Mr. Abbas of inciting the violence.

"We will respond with a heavy hand to the brutal murder of Jews who came to pray and were met by reprehensible murderers," he said, threatening to destroy the homes of the attackers.

Underscoring concerns about the potential for Jewish vigilantes to take revenge, the police chief warned Israelis not to take the law into their own hands.

In the evening, hundreds of right-wing Israeli demonstrators chanted "Death to Arabs" and blocked streets at the main entrance to Jerusalem as well as at the light rail line. A far right Israeli politician, Michael Ben Ari called for the "transfer" of Palestinians from Israeli control The Israeli police said they arrested more than two dozen demonstrators.

In the Palestinian neighborhood of Jabel Mukaber, the home of the attackers, Israeli riot police clashed with Palestinians who shot firecrackers at them.

The unrest in Jerusalem was initially triggered in July by the killing of a Palestinian teen by Israelis seeking revenge for the killing of three Israeli teenagers.

In the last two months, six Israelis, including an infant, have been killed in car rampages and knife attacks-an escalation of violence that reminds many of two Palestinian uprisings in the late-1980's and early 2000s.

The killings at the synagogue came a day after an Arab bus driver was found hanged in a commuter bus. Israeli authorities described it as a suicide but Palestinians disputed that, alleging that Israelis were responsible. In the hours after the body was found, rioting broke out briefly in several Arab neighborhoods of Jerusalem.

U.S. Secretary of State John Kerry urged Palestinian leaders to condemn the attack.

"To have this kind of act, which is a pure result of incitement...is unacceptable," he said.

As tensions spiraled, the Obama administration moved swiftly both to condemn the attack and to exhort both sides to work to end the violence, fearing a wider cycle of unrest and further destabilization.

Mr. Kerry spoke Tuesday with Mr. Netanyahu to offer condolences and U.S. support. Mr. Kerry also spoke with Mr. Abbas, approving of the Palestinian leader's condemnation of the attack, State Department spokesman Jeff Rathke said.

The White House, which for days has voiced growing concern over tensions in the area stemming in part from stepped-up Israel construction in disputed areas, called for calm.

Among U.S. concerns are increased tensions from Israel's practice of punitive home demolitions for attackers. Mr. Rathke said the U.S. view is that such measures "are counterproductive to the cause of peace," a view Mr. Kerry has expressed to Israeli officials.

An Israeli police official said three of the victims were rabbis who had emigrated from the U.S. to Israel.

The British government confirmed that the fourth victim was a British-Israeli national.

Among the Americans killed was a well-known rabbi, Moshe Twersky, who was 59 years old. Raised in the Boston area, Mr. Twersky came from a prominent Jewish family. His father founded Harvard University's Center for Jewish Studies, and a grandfather, Joseph B. Soloveitchik, who was a key figure in modern orthodox Judaism.

Seven people, two of them policemen, were injured, Israeli police said. One of the two policemen died of his wounds later Monday night. The wave of violence in Jerusalem pits Arab residents against Jewish neighbors.

Unlike past waves of violence that came from Palestinians in the West Bank and Gaza, these attacks are originating from places Israel considers within its territory.

More than 250,000 Palestinians live in East Jerusalem, territory Israel conquered in the 1967 Middle East war and subsequently annexed-a move that was never recognized by many countries including the U.S. While Arab residents of East Jerusalem weren't granted Israeli citizenship, they enjoy free movement throughout the country, carry Israeli identification cards and can vote in municipal elections. Michael Oren, a historian and former Israeli ambassador to the U.S., compared the attacks in Jerusalem to homegrown terrorists in Western countries.

"For Israeli security forces, this is a different type of challenge," he said. "We're also dealing with copycat attacks now and stabbings that can be at random and spontaneous. That is difficult from a security standpoint to predict and interdict."

Ofer Shelah, a Knesset member who heads the parliament's defense and security committee said the attackers likely carried the same identity cards as he did.

Ghassan Al Khatib, a former Palestinian minister, said the internal threat Israel is now encountering was a product of its own making. While the country granted some privileges to Palestinians living in Jerusalem, he said Israel never followed through with equal treatment of them, breeding animosity unseen even in the West Bank.

"After 40 years of attempts to annex East Jerusalem by Israel, we're seeing resistance to it still," he said.

The foreign ministry identified the victims as Rabbi Aryeh Kupinsky, 43; Rabbi Abraham Shmuel Goldberg, 68; Rabbi Kalman Ze'ev Levine, 55; and Rabbi Twersky. A spokesman for Canada's Foreign Affairs Department said a dual Canadian-Israeli citizen was among those injured, but didn't identify the person or say how severe the injuries were.

Local Palestinian residents identified the attackers as Ghassan Abu Jamel, 27, and Odai Abu Jamel, 22, cousins from Jabel Mukaber, a neighborhood in East Jerusalem.

Yosef Posternak said he was in mid-prayer in a room with about 20 others when he heard shots.

"I turned around and I saw a man with a gun start to fire on people at point-blank range, and immediately afterward a person with a butcher's knife entered and went on a rampage in all directions," he said.

-Peter Stiff, Paul Vieira and Felicia Schwartz contributed to this article.