Emergency personnel remove a body from the scene. Among the dead were three dual U.S.-Israeli citizens. Abir Sultan / EPA

An ultra-Orthodox Jew looks at a bullet hole in a drape covering the ark in the synagogue where the attack took place. The two attackers were shot to death by Israeli police. Finbarr O'Reilly / Reuters

Covered bodies at the scene of an attack on a Jerusalem synagogue, Nov. 18, 2014, after two Palestinians armed with axes and guns entered the temple and killed four worshippers. Reuters

An attack on a synagogue in Jerusalem in which four worshippers and a police officer were killed by Palestinian attackers — later shot dead by police — has ramped up tensions in the region, with Israel vowing a “harsh” response to the latest act of violence.

The two assailants stormed the Har Nof Synagogue armed with axes and guns before engaging in a shoot-out with security forces. One officer succumbed to injuries sustained in the shootout later on Tuesday and another was injured.

The attack represents the deadliest such incident in the holy city for six years and comes on the back of incessant tit-for-tat reprisal attacks in recent weeks. Among the dead were three American-Israeli and one British-Israeli dual nationals, Israeli police said.

Tensions have been high in Jerusalem over access to the city’s holiest site and over Israeli settlement in the occupied eastern part of the city. But Tuesday's attack shattered the tranquillity that prevailed in the western parts of the city despite the tensions of recent weeks.

In the weeks leading up to Tuesday’s attack, five Israelis and a foreign visitor have been killed in attacks in Jerusalem, the West Bank and Tel Aviv. Meanwhile, about a dozen Palestinians have also been killed, including the two men responsible for the synagogue attack.

Late on Sunday, a Palestinian bus driver was found hanged in his vehicle. Israeli police said he committed suicide, but Palestinians said he was killed by Israeli settlers.

The latest attack is likely to spur more violence. After the synagogue attack, Israeli police entered some predominantly Palestinian areas in Jerusalem to make arrests. They were met with protesters armed with stones. Police responded with tear gas.

Leaders on both sides did little to tamp down tensions in the immediate aftermath of the synagogue attack.

Israeli Prime Minister Benjamin Netanyahu vowed to "respond harshly" to the incident, describing the attack as a "cruel murder of Jews who came to pray and were killed by despicable murderers." He immediately ordered the demolition of the assailant's homes, as well as homes of Palestinians who carried out several other recent attacks.