Four people killed in synagogue attack in Jerusalem Two men, thought to be Palestinians armed with axes, knives and guns have killed at least four people in a Jerusalem synagogue. Worshippers were fired upon at a Jewish Synagogue in Jerusalem. Picture:AFP/ Gali Tibbon Source: AFP TWO Palestinian cousins armed with meat cleavers and a gun stormed a Jerusalem synagogue during morning prayers, killing four people in the city's bloodiest attack in years. Police killed the attackers in a shootout. The attack ratcheted up fears of sustained violence in the city, which is already on edge amid soaring tensions over its most contested holy site. Police said the dead worshippers were three Americans and a Briton, and that all held dual Israeli citizenship. The attack occurred in Har Nof, an ultra-Orthodox neighbourhood that has a large population of English-speaking immigrants. Grief...Ultra-Orthodox Jews mourn at the site of the attack. US President Barack Obama has condemned the "horrific attack" on a Jerusalem synagogue that left four people, including three US citizens, dead, and called for calm. "At this sensitive moment in Jerusalem, it is all the more important for Israeli and Palestinian leaders and ordinary citizens to work cooperatively together to lower tensions, reject violence, and seek a path forward towards peace," Mr Obama said. Mr Obama identified the three Israeli-Americans who died in Tuesday's attack by two Palestinians armed with a gun and meat cleavers as Aryeh Kupinsky, Cary William Levine and Mosheh Twersky. "There is and can be no justification for such attacks against innocent civilians," he said. The thoughts and prayers of the American people are with the victims and families of all those who were killed and injured in this horrific attack and in other recent violence. Twersky, the grandson of a renowned rabbi from Boston, Joseph Soloveichik, was the head of Yeshivas Toras Moshe, a religious seminary for English-speaking students. Israeli authorities identified the British man as Avraham Goldberg. Eight more people were also wounded. Israel's Prime Minister Benjamin Netanyahu vowed to "respond harshly," describing the attack as a "cruel murder of Jews who came to pray and were killed by despicable murderers." Mourning ... Orthodox Jews carry the body of Mosheh Twersky during his funeral in Jerusalem. One Canadian was wounded in the attack, said Francois Lasalle, a spokesman for Canada's Foreign Affairs Department. He declined to provide further details. Palestinian President Mahmoud Abbas condemned the attack, the first time he has done so since a recent spike in deadly violence against Israelis. He also called for an end to Israeli "provocations" surrounding a sacred shrine holy to both Jews and Muslims. The attack was the deadliest in Jerusalem since a Palestinian assailant killed eight students at a Jewish seminar in March 2008. Mourning ... an Orthodox Jewish man cries during the funeral of victim Rabbi Moshe Twersky in Jerusalem. Picture: AP Source: Getty Images Police spokeswoman Luba Samri identified the assailants as Ghassan and Oday Abu Jamal from the Jabal Mukaber neighbourhood in east Jerusalem, the section of the city captured by Israel in 1967 and claimed by the Palestinians as their capital. The Popular Front for the Liberation of Palestine, a small militant group, said the cousins were among its members, though it did not say whether it had instructed them to carry out the attack. Hamas, the militant Palestinian group that runs the Gaza strip, praised the attack. Bloody scene ... an Israeli emergency services member cleans blood from the sidewalk at the scene of the attack. In Gaza, dozens took to the streets to celebrate, with some offering trays full of candy. Israeli police spokesman Micky Rosenfeld said six people were wounded in the attack, including two police officers. Four were reported in serious condition. Associated Press footage showed wounded worshippers being assisted by paramedics, and a bloodied meat cleaver lay nearby. Footage released by the Israeli government showed blood-soaked prayer books and prayer shawls on the floor of the synagogue. Four killed ... a handout picture obtained from the Israeli Government Press Office (GPO) shows the scene of the attack inside a synagogue. A photo in Israeli media showed a body on the floor, covered with a prayer shawl. Yosef Posternak, who was at the synagogue at the time of the attack, told Israel Radio that about 25 worshippers were inside when the attackers entered. I saw people lying on the floor, blood everywhere. People were trying to fight with (the attackers) but they didn't have much of a chance," he said. Soon after the attack, clashes broke out outside the assailants" home, where dozens of police officers had converged. Prayer ... an Ultra-orthodox Jewish man puts his head in his hands inside the synagogue. Residents hurled stones at police, who responded using riot dispersal weapons. Neighbourhood residents, speaking on condition of anonymity for fears for their own safety, said 14 members of the Abu Jamal family were arrested. Mohammed Zahaikeh, a social activist in Jabal Mukaber, said a relative of the cousins had been released in a 2011 prisoner swap and rearrested recently by Israeli police. Aftermath ... Israeli emergency personnel walk past blood on the floor in the synagogue. Israel has been on edge with a spate of attacks by Palestinians against Israelis, killing at least six people in Jerusalem, the West Bank and Tel Aviv in recent weeks before Tuesday's casualties. The violence has created a special security challenge for Israel, since most of the attackers come from east Jerusalem. More than 200,000 Arab residents there hold residency rights that, in contrast to Palestinians in the neighbouring West Bank, allow them to move freely throughout Israel. Attackers ... a relative displays photos of cousins Ghassan, right, and Oday Abu Jamal at the family home in Jerusalem after the cousins stormed a Jerusalem synagogue on, attacking worshippers with meat cleavers and a gun during morning prayers and killing four people before they were killed in a shootout with police. Israel's police chief said Tuesday's attack was likely not organised by militant groups, making it more difficult for security forces to prevent the violence. These are individuals who decide to do horrible acts. It's very hard to know ahead of time about every such incident," Yohanan Danino said. Celebration ... a gunman from the Popular Front for the Liberation of Palestine distributes sweets in the Palestinian refugee camp of Ein el-Hilweh to celebrate the attack. US Secretary of State John Kerry blamed the attack on Palestinian calls for "days of rage," and said Palestinian leaders must take serious steps to refrain from such incitement. He also urged Palestinian leaders to condemn the attack "in the most powerful terms." "This morning in Jerusalem, Palestinians attacked Jews who were praying in a synagogue," Mr Kerry said. He commented after speaking by phone with Israeli Prime Minister Benjamin Netanyahu. "Innocent people who had come to worship died in the sanctuary of a synagogue," Mr Kerry said, his voice quavering. They were hatcheted, hacked and murdered in that holy place in an act of pure terror and senseless brutality and murder. I call on Palestinians at every single level of leadership to condemn this in the most powerful terms. This violence has no place anywhere, particularly after the discussion that we just had the other day in Amman. U. S. Secretary of State John Kerry arrives for a breakfast meeting with Britain's Foreign Secretary Philip Hammond in London. Mr Kerry called the attack an "act of pure terror and senseless brutality and violence." The FBI routinely investigates attacks abroad in which US citizens are killed and is expected to be involved in this investigation as well, a US official in Washington said, speaking on condition of anonymity because the official was not authorised to speak on the record. British Foreign Secretary Philip Hammond also condemned the violence. Much of the recent violence stems from tensions surrounding the Jerusalem holy site referred to by Jews as the Temple Mount because of the Jewish temples that stood there in biblical times. It is the most sacred place in Judaism; Muslims refer to it as the Noble Sanctuary, and it is their third holiest site, after Mecca and Medina in Saudi Arabia. Rising violence ... a Palestinian uses a slingshot to throw back a tear gas canister that was fired by Israeli troops during clashes with Israeli soldiers, outside the Ofer military prison, near the West Bank city of Ramallah after the attacks. The site is so holy that Jews have traditionally refrained from going there, instead praying at the adjacent Western Wall. Israel's chief rabbis have urged people not to ascend to the area, but in recent years, a small but growing number of Jews, including ultranationalist lawmakers, have begun regularly visiting the site, a move seen as a provocation. Victim ... Israeli emergency personnel remove the body of an Israeli man from the synagogue. The attack comes as tensions appeared to have been somewhat defused last week following a meeting by Israeli Prime Minister Benjamin Netanyahu, Kerry and Jordan's King Abdullah II in Jordan. The meeting was an attempt to restore calm after months of violent confrontations surrounding the sacred shrine.