The international community condemned Tuesday's assault on a Jerusalem synagogue that left four Israelis dead and called for restraint from both sides, while two Palestinian groups applauded the attack.

On Tuesday, two Palestinians armed with a gun and axes burst into a Jerusalem synagogue and killed four Israelis before being shot dead.

The Islamist movement Hamas and the leftist Popular Front for the Liberation of Palestine (PFLP) – which claimed responsibility for the attack – defended the operation.

PFLP's military wing, the Abu Ali Mostafa Brigades, said in a statement that the attack was carried out as a "natural response to the crimes of the [Israeli] occupiers," as AFP reported.

PFLP is a revolutionary leftist organisation known for its armed attacks on Israeli targets and aircraft hijackings. Its armed brigade has previously declared responsibility for many attacks during the Al-Aqsa Intifada in 2000.

Meanwhile, Palestinian President Mahmoud Abbas joined the international community in denouncing the violence and called on both sides to avoid escalation.

Israeli Prime Minister Benjamin Netanyahu said the attack was the result of "incitement" by Abbas as well as Hamas.

"This is the direct result of incitement by Hamas and Abu Mazen (Abbas), that the international community ignores in an irresponsible manner," Netanyahu said.

In a statement on his Facebook page, Netanyahu was quoted as saying: "We will respond with a heavy hand to the brutal murder of Jews who came to pray and were met by reprehensible murderers."

The first international reaction came from US State Secretary John Kerry, who described the attack as an "act of pure terror and senseless brutality." Kerry later made a phone call to Abbas and discussed the possible means for avoiding escalation.

French President Francois Hollande also condemned the attacks in a press statement while also denouncing how some parties hailed the attacks, Egypt's state-run news agency MENA reported.

Rupert Colville, the UN's High Commissioner for Human Rights, released a statement calling on both sides to exercise restraint.

"We urge Israeli authorities to refrain from taking measures, such as punitive demolitions, which violate international law and may further inflame the situation," Colville said.

"We call on Israelis and Palestinians to exercise restraint, and for all responses to the escalating situation in Israel and the Occupied Palestinian Territory to be grounded in respect for human rights."

His comments come after Israel announced it would loosen restrictions on carrying weapons, according to AFP, quoting Israeli Public Security Ministry Yitzhak Aharonovitch.

Aharonovitch pointed out that the new rules would apply to "anyone with a license to carry a gun, such as private security guards and off-duty army officers."

The EU's foreign policy chief, Federica Mogherini, said the attack was an "act of terror" against worshipers at morning prayers.

"The lack of progress towards the two-state solution will systematically ensure the next round of violence. The time has come for both sides to make compromises, promote stability and ensure long-term security for both Israelis and Palestinians," Mogherini stated.

Tensions between Palestinians and Israelis have been escalating due to Palestinian fears of Israel authorising Jewish prayers inside Al-Aqsa Mosque, the third holiest place to Muslims, as Tel Aviv continues its settlement plans in the occupied West Bank.

On November 3, Israel's interior ministry approved the construction of about 500 new settlements in East Jerusalem. Netanyahu, one month earlier, vowed to build more than 1,000 new settler homes.

Yassin Sbeih, a Palestinian activist, told Ahram Online that Palestinians are reacting in response to Israeli actions towards them.

"Palestinians in the West Bank – especially in Al-Khalil city, Bethlehem, Ramallah and other areas and refugee camps in the West Bank – are confronting Israeli bullets every day, with many people arrested," Sbeih argued.

The activist also highlighted how the July-August Israeli offensive on the Gaza Strip has impacted the situation in the West Bank. "Gazans are exhausted after the war," he emphasised.

Israel's assault on Gaza, stopped by an Egypt-brokered ceasefire deal, left more than 2,000 Palestinians dead, with more than 12,000 injured. Over 70 Israelis died in the violence.

The 50-day offensive left over 100,000 Palestinians displaced, with about 57,000 living in communal shelters.