Security was tight in Jerusalem on Wednesday morning, a day after four rabbis and a policeman were crudely killed in a deadly attack on a synagogue.br br It was carried out by two Palestinian cousins armed with a gun, knives and a meat cleaver. br br The militant Popular Front for the Liberation of Palestine claimed responsibility for the onslaught, calling it a “heroic operation.”br br Palestinian President Mahmoud Abbas strongly condemned the attack.br br Less than 24 hours later, worshippers returned to the synagogue in the ultra-Orthodox Jewish neighborhood of Har Nof in West Jerusalem.br br Unrest has grown since the 50-day Israeli war on Gaza during which more than 2,000 Palestinians were killed by Israeli forces, including at least 500 children.br br The movement of dozens of Jewish settlers into a predominately Arab neighbourhood in East Jerusalem in recent weeks has increased tensions.br br A push by militant Jews to be allowed to pray at a site in Jerusalem’s Old City that is holy to both Jews and Muslims,in defiance of a decades-long ban agreed by Israel, has also fuelled anger.