Four rockets were launched from Syria toward the Israeli-controlled Golan Heights at dawn on Tuesday, setting off air-raid sirens but causing no harm, according to the Israeli military.

The military said that the incoming fire was intercepted by Israel’s Iron Dome air defense system and that it appeared no rockets had fallen on the Israeli-controlled side of the line.

It was not immediately clear if the rocket fire from Syria was meant as a surprise attack or came in response to Israeli activity across its northern frontier. Around the same time as the rocket launches, Sana, the official Syrian news agency, reported that explosions were heard in the vicinity of the Damascus airport.

An Israeli military spokeswoman had no comment on the report from Syria.

After decades of quiet, there have been occasional exchanges of fire across the old Israeli-Syrian armistice line as Israel has worked, mostly clandestinely, to curb Iran’s growing influence in Syria, largely under cover of the chaos of Syria’s civil war.