A policeman injured during a deadly attack in a Jerusalem synagogue has died in hospital.

Four rabbis were killed as two armed Palestinian men entered the building - before being shot dead.

Israeli Prime Minister Benjamin Netanyahu has promised to "settle the score" while President Obama has appealed for calm.

The attack took place at around 7am local time at the synagogue in the ultra-Orthodox Har Nof neighbourhood, which has a large number of immigrants from Western countries.

Both attackers were shot dead by police at the scene. They have been named as cousins Ghassan and Oday Abu Jamal, from the Jabal Mukaber area in east Jerusalem.

The Popular Front for the Liberation of Palestine has claimed the two cousins were members, but it has not said if it had instructed them to carry out the attack.

Six people were injured during the attack, including two police officers. Four are said to be in a serious condition.