Police spokeswoman Luba Samri said the truck veered off course and rammed into the group in the Armon Hanatziv neighborhood. She said the attacker was shot dead, according to The Associated Press.
Paramedic Chen Lendi Sharon was among the first to arrive on the scene and described 10 bodies trapped beneath the truck.
Read alsoU.S. seeks death penalty as Esteban Santiago charged with massacre at Florida airportIsrael's rescue service MDA said the four casualties were in their 20s and included three women and a man. Of the 15 wounded, one was in serious condition.
Israel's police chief Roni Alsheich told reporters the attacker was from an Arab neighborhood in east Jerusalem and forces had no advance warning. He refused to elaborate and a gag order was placed on further details pending an investigation.
It would rank as one of the deadliest in a more than yearlong wave of Palestinian shooting, stabbing and vehicular attacks against Israelis that had slowed of late. Sunday's incident marks the first Israeli deaths in three months.
