JERUSALEM — Iranian forces in Syria fired about 20 rockets into the Israeli-controlled Golan Heights early Thursday, targeting forward positions of the Israeli military, according to a military spokesman.

The spokesman, Lt. Col. Jonathan Conricus, said Israel had responded to the attack but did not provide details. If confirmed, this would be the first rocket attack carried out directly by Iran, rather than by one of its proxies, against Israel.

Colonel Conricus said that several of the rockets had been intercepted by the Iron Dome missile defense system. He said that he was not aware of any casualties and that damage to Israeli facilities was low.

The Israeli military said in a statement that it “views this event with great severity and remains prepared for a wide variety of scenarios.” The Syrian state news agency reported that the country’s air defenses responded to at least two waves of Israeli missile attacks after the strike against the Israeli positions.