Two Israeli officials told Iran International that "Iran's attacks on Israel tonight will not go unanswered," as Israeli, US, UK and Jordanian air forces downed dozens of incoming Iranian drones.

However, the Israeli officials did not specify the nature of the response or its timing.

Israel's military said it was sounding sirens in locations throughout the country early on Sunday, as Iran International’s live broadcast from Israel showed multiple interceptions of incoming projectiles.

Although it was not clear if drones or missiles were being destroyed by multiple Israeli air defense systems, our correspondent believed some anti-missile defenses were also operating at around 2:00 am local time.

Israel's Magen David Adom ambulance service said early on Sunday that it had received no word of any casualties from Iranian drones launched at the country, many of which local media described as having been intercepted.

Jordanian jets downed dozens of Iranian drones flying across northern and central Jordan heading to Israel, two regional security sources told Reuters.

The sources said the drones were brought down in the air on the Jordanian side of the Jordan Valley and were heading in the direction of Jerusalem. Others were intercepted close to the Iraqi-Syrian border. They gave no further details.

Israel plans a "significant response" to the unprecedented Iranian drone salvo against it, top-rated Channel 12 TV quoted an unnamed senior Israeli official as saying early on Sunday.

An Israeli defense official told Army Radio that more than 100 Iranian drones have already been intercepted outside of Israeli airspace, out of hundreds fired at Israel.

The report said the drones were downed by the United States and the United Kingdom. Earlier, the IDF said it had identified more than 100 drones heading toward Israel.

Follow developments on Iran International's Live coverage of ongoing tensions between Iran and Israel.