A doctor who recently immigrated from Canada to Israel was among the first responders at the scene of a synagogue in Jerusalem, where two Palestinian cousins attacked and killed four worshippers during early-morning prayers.

At least six other people were wounded Tuesday morning, one of them a Canadian , when the two men stormed the building armed with a gun and meat cleavers, Israeli police said. Officers eventually killed the attackers in a shootout.

Dr. Joyce Morel, who used to work as an emergency physician in Brampton, Ont., said that when she arrived at the synagogue she saw an injured man sitting outside the building.

Police came running out as she tended to him because the assailants were still shooting inside the synagogue, she said. Officers ordered her and other first responders to clear the scene.

Morel said she treated multiple patients, many with severe injuries.

"There was one police officer who had been shot in the head, and had massive head bleeding," she told CTV News Channel. "Another one had been shot in the thigh, and was bleeding from an artery.

"The man who I first started with had been stabbed with a cleaver in the back of his chest, very deep down."

Morel, who had previously worked in an Ontario emergency room, said it was disturbing to be treating people at the scene of the attack.

"It's very different treating people at the scene from intentional injuries like this… it's quite jarring," she said.

Police have identified the assailants as Palestinian cousins Ghassan and Oday Abu Jamal. The Popular Front for the Liberation of Palestine said the cousins were among its members.

With files from The Associated Press