US and British warplanes were reported to have downed some Israel-bound Iranian drones late on Saturday, as Israel’s allies rallied to help it defend itself from an unprecedented multi-pronged attack from Tehran.

The White House said the “airborne attack” against Israel was likely to “unfold over a number of hours” and reiterated its “ironclad support” for the Jewish state’s security.

Joe Biden cut short a weekend trip to his Delaware beach home to return to the White House and convene a meeting of his top national security team.

Britain has also rallied to Israel’s side, with Rishi Sunak condemning the “reckless” action in the “strongest terms”.

The Prime Minister said that the strikes risked “destabilising” the Middle East and that the UK would work with its allies to “prevent further escalation”.

On Saturday night it was reported that British fighter jets took off from Cyprus in order to intercept drones and missiles launched from Iran towards Israel.

Israel’s Channel 12 reported that US and UK fighter jets have shot down Iranian drones near the Syria-Iraq border.

When asked about the missile strikes, the Ministry of Defence did not comment.

When the UK launched a series of air strikes against the rebel Houthi group earlier this year, Britain used its Akrotiri base in Cyprus to launch four Typhoon combat planes.

Rear Adm Daniel Hagari, Israel Defense Force spokesman, said Iran launched over 100 drones directly from within its territory, in an apparent effort to overwhelm Israel’s air defences.

It set up a direct military confrontation between the regional foes in a major escalation that raised the risks of a wider war.

“We are working in close cooperation with the United States and our partners in the region in order to act against the launches and intercept them,” he said in a televised statement.

Channel 12, an Israeli news network, reported that the US had been the first to warn Israel the attack was incoming.

The network also reported that US and British warplanes downed some of the Iranian drones over the Iraq-Syria border area, without citing its sources.

Iraq, which is on the flight path between Iran and Israel, closed its airspace in anticipation of the attack.

Jordan’s air defences were last night bracing to intercept and shoot down any Iranian drones or aircraft that violate its airspace, two regional security sources told Reuters.

They said the army was also in a state of high alert and radar systems were monitoring any drone activity coming from the direction of Iraq and Syria.

However, Jordan’s communications minister denied reports the country had closed down its airspace or declared a state of emergency.

Tensions are at their highest since the Israel-Hamas war began six months ago after a suspected Israeli strike this month on an Iranian consular building in Syria killed 12 people, including two senior Iranian generals in the Islamic Revolutionary Guard Corps’ elite Quds Force.

Iran had promised to retaliate against Israel, and US and Israeli officials were on high alert for an attack as soon as this weekend, raising concerns about the conflict escalating into a wider regional war.

Washington feared an attack could be imminent and rushed warships into position on Friday, including moving the USS Eisenhower aircraft carrier and three other warships closer to Israel in the northern Red Sea.

Multiple RAF transport aircraft were in the air over the eastern Mediterranean shortly after the attack was first reported.

RAF A400 took off from Brize Norton at 4.53 UK time and headed for Syria before GPS dropped. 

Adrienne Watson, the spokeswoman for the US National Security Council, said Mr Biden was being “regularly updated by his national security team”, which was “in constant communication with Israeli officials as well as other partners and allies”.

She added: “President Biden has been clear: our support for Israel’s security is ironclad. The United States will stand with the people of Israel and support their defence against these threats from Iran.”

In a statement released on Saturday night, Rishi Sunak said: “The UK will continue to stand up for Israel’s security and that of all our regional partners, including Jordan and Iraq.

“Alongside our allies, we are urgently working to stabilise the situation and prevent further escalation. No one wants to see more bloodshed.”

Iran’s state-run IRNA news agency claimed the multi-pronged attack involved rockets, ballistic missiles and drones fired at Israel from Syria, Iran, Iraq, and Yemen.

Israeli and allied forces were expected to attempt to intercept them before they arrived.

Israel’s “Iron Dome” missile-defence system has shown itself capable of defending the country against small volleys of incoming fire, but analysts warned it could potentially be overwhelmed by a massive missile barrage.

The drones launched from Iran were seen flying low as they passed over Iraq, with social media awash with clips of the weapons making a loud buzzing noise.

Israel and its neighbours’ decision to shut down their airspace in anticipation has left British travellers facing disruption.

Flight times are expected to be longer as airlines avoid Iranian airspace and air fares are also expected to increase.

Israel’s El Al Airlines was reported to have cancelled 15 flights scheduled over Saturday and Sunday, and Austrian Airlines was also reported to have cancelled all its flights to Iran until April 18.

United Airlines said it had cancelled its service to Tel Aviv.

“We have cancelled Saturday’s planned flight from Newark to Tel Aviv and its associated return flight due to restrictions on Israeli airspace,” a spokesman said.

“We are closely monitoring the situation and will make decisions on upcoming flights with a focus on the safety of our customers and crews.”

‘Security is our priority’

A Lufthansa spokesman, on behalf of the firm including its subsidiary Austrian Airlines, said: “We have temporarily stopped overflying Iranian airspace until April 18. Security is our number-one priority.”

Qantas had already paused its non-stop flights from Perth to London in a bid to avoid Iranian airspace due to fears of the impending attack on Israel.

The route has now been changed and has a stop in Singapore in place due to the situation.

A Qantas spokesman said: “We’re temporarily adjusting the flight paths for our flights between Perth and London due to the situation in parts of the Middle East. We’ll reach out to customers directly if there’s any change to their booking.”

The UK along with the US were among the countries issuing a travel warning to those looking to travel to the region, along with France, Canada and Australia.

Dutch airline KLM also said it would no longer fly over Iran or Israel, according to Dutch press agency ANP on Saturday.

KLM, the Dutch arm of Air France-KLM, said the move was a precaution, but it indicated it would continue flying to Tel Aviv.