Mohammad Haytham Tamimi was receiving treatment in an Israeli hospital after being shot in the head while travelling by car with his parents. His father was shot in the shoulder.
The boy's mother told Israeli news organisation Haaretz that the shooting “was like an execution”.
Israel's military said its personnel were returning fire at Palestinian gunmen who were shooting at the settlement of Neve Tzuf on Thursday.
The military later released a statement saying it “regrets harm to non-combatants and is committed to doing everything in its power to prevent such incidents”. The statement added that the shooting was “under review”.