An Israeli defense official told Israel Military Radio that more than 100 Iranian drones have already been intercepted outside Israel's airspace and hundreds have been fired at Israel.
According to the report, the drones were shot down by the US and the UK.
Earlier, the IDF said it had identified more than 100 drones headed toward Israel.
Evidence: The Times of Israel
CNN: Explosions were reported in the sky in several parts of Israel and the West Bank
CNN crews on the ground report explosions over Tel Aviv, which appear to have been intercepted by Israeli air defenses.
There were reports of explosions in the West Bank's Beersheba, Dead Sea and Hebron areas, as well as the Golan Heights on the border with Syria.
According to live webcams seen by CNN, Iron Dome interceptions took place at several additional locations.
Interceptions were observed above Hanatan in northern Israel, east of Haifa; Near Nazareth; Near Modiin-Maccabim-Reyud; and Safed, near the Golan Heights.
Sirens sound as air defenses are activated in many parts of Israel.
