JERUSALEM - Prime Minister Stephen Harper says Canada condemns today's deadly attack on a Jerusalem synagogue.

Israeli officials say two Palestinians attacked worshippers with meat cleavers and a gun during morning prayers -- killing four people -- before they were killed in a shootout with police.

Harper says on Twitter that Canada "condemns the barbaric act of terror" and adds: "Our thoughts and prayers are with the people of Israel."

Israel's Prime Minister Benjamin Netanyahu says Israel will "respond harshly."

He called the attack a "cruel murder of Jews who came to pray and were killed by despicable murderers."

U.S. Secretary of State John Kerry also denounced the attack, calling it an "act of pure terror and senseless brutality and violence."

Meanwhile, Palestinian President Mahmoud Abbas is also condemning the attack -- the first time he has done so since a recent spike in deadly violence against Israelis.

Abbas also called for an end to Israeli "provocations" surrounding the sacred site.

The attack is the deadliest in Jerusalem in years and it's feared it will ratchet up fears of sustained violence in the city.