One of the victims of this morning's deadly attack at a Jerusalem synagogue has been identified as the "Rosh Kollel" of the Torat Moshe yeshiva, Rabbi Moshe Twersky.

Torat Moshe Yeshiva,  sometimes called ToMo for short by its students, is an advanced level English-speaking yeshiva named for Rabbi Moshe Soloveitchik and founded by his grandson, Rabbi Moshe Meiselman.  

Rabbi Twersky was among four people murdered when two Palestinian terrorists stormed the Kehillat Bnai Torah Yeshiva Synagogue in Jerusalem's Har Nof neighborhood armed with axes, knives and guns during morning prayers.

Eight other people were injured in the ensuing slaughter - four of them seriously. Harrowing pictures from the scene showed bodies still wrapped in their prayer shawls (tallitot) and tefilin scattered on the floor.

Rabbi Twersky's funeral will begin at 14:00 today from the Beit HaTalmud yeshiva in Har Nof.

The terrorists have been identified as cousins Uday and Rassan Abu Jamal, from the eastern Jerusalem neighborhood of Jabel Mukhaber.

The pair were killed in a gunfight with police first-responders, two of whom are among the wounded.

Magen David Adom paramedics who arrived at the scene initially encountered only one body - but the scope of the massacre soon became clear when they entered further into the building.

Eye-witnesses have told of the gruesome scene as the attack unfolded.

"There were people running from the synagogue, and a man sitting on the pavement covered in blood, it looked like he has been stabbed," said local resident Sarah Abrahams, who was walking past when it happened.

"Two people came out with their faces half missing, looking like they'd been attacked with knives," she said as hundreds of hareidi Jews pressed up against the police tape, a few chanting "Death to terrorists."

Fighting back tears, Moshe Eliezer said he had narrowly avoided being at the scene after oversleeping.

"This is a yeshiva community. Ninety percent don't serve in the army. We're not violent," he said.  

Police said six people were wounded, among them two policemen who had engaged in a gunbattle with the terrorists.  

They said the attackers were two cousins from the eastern Jerusalem neighborhood of Jabal Mukaber.  

Speaking to journalists at the scene, Jerusalem Mayor Nir Barkat expressed shock at the scale of the bloodshed.  

"To slaughter innocent people while they pray... it's insane," he said.