Iranian media had reported that Iran's Revolutionary Guards carried out a joint missile operation against Israel with Tehran's Lebanese ally Hezbollah.

Israel said that it was in turn carrying out "wide-scale" strikes on Tehran and a Hezbollah stronghold in Lebanon's capital.

On two separate occasions Thursday, the Israeli military urged people in affected areas to head to shelters, as it said it "identified missiles launched from Iran toward the territory of the State of Israel".

"Defensive systems are operating to intercept the threat," the military said on its official Telegram channel both times.

The Israeli military said in a separate post on Telegram that it "struck 10 terror structures in the Dahieh area (of south Beirut) within 30 minutes, including intelligence headquarters, a headquarters of the Radwan unit, and additional command centres."

Sirens sounded across Israel throughout the early hours of Thursday, including in Jerusalem according to AFP correspondents.

After the first wave of missiles fired by Iran, the Magen David Adom emergency services said that there were no reported casualties following the missile fire, although paramedics were deployed to treat individuals who fell over on the way to shelters.