British fighter jets have been deployed to shoot down drones fired at Israel from Iran.
In a statement, the Ministry of Defence (MoD) said the Royal Air Force (RAF) will repel “any airborne attacks within range” of operations in the region.
It is understood RAF jets have flown over Iraq and Syria but not Israel.
PM Rishi Sunak condemned Iran’s “reckless attack”, pledging the UK would “continue to stand up for Israel’s security”.
Iran launched dozens of aerial drones and cruise missiles at Israel overnight on Saturday and into Sunday, in a widely anticipated and unprecedented retaliatory attack.
The Israeli military said it had intercepted the majority of the attacks – mostly outside of Israel’s airspace – with the help of other countries.
The US was one of those allies, with President Joe Biden confirming the US military helped Israel shoot down “nearly all” of Iran’s drones and missiles.
Jordan also assisted in taking out some Iranian drones, according security sources cited by the Reuters news agency.
The MoD has not said how many RAF Typhoons were airborne over Syrian and Iraqi airspace, nor confirmed whether they successfully shot down any targets.
But its statement made clear that RAF aircraft would intercept any attacks within the areas it already operates in as part of the Operation Shader mission against the Islamic State group.
Defence Secretary Grant Shapps confirmed the move on X, formerly known as Twitter, and said that he “strongly condemned the senseless airborne attack” by Iran.
Mr Sunak also responded to Iran, adding that the “strikes risk inflaming tensions and destabilising the region”.
“Iran has once again demonstrated that it is intent on sowing chaos in its own backyard,” the prime minister said.
He went on pledge the UK’s continued support for the security of Israel and the UK’s other allies in the region – including Jordan and Iraq.
Iran’s attacks come after Tehran vowed to retaliate over a strike on its consulate in Syria on 1 April, which killed seven IRGC officers, including a top commander.
The Iranian government has accused Israel of carrying out that attack, but Israel has neither confirmed nor denied it.
Labour leader Sir Keir Starmer said the party supported all measures “designed to restore calm” and prevent a wider regional war.
In a statement, he condemned Iran’s “decision to subject Israelis to these unacceptable attacks”.
“The international community has been united in urging restraint and we regret that yet again Iran has chosen a different, dangerous path,” Mr Starmer added.
Conservative MP Tobias Ellwood, who chaired the Commons Defence Select Committee until his resignation over comments made about Taliban-rule in Afghanistan, told BBC Breakfast: “When it comes to a state-on-state attack, it’s very clear that Britain will stand with Israel to defend its skies and soil.”
But he said allies would be encouraging Israel “to take stock, to think carefully before responding otherwise this could tie the Middle East up into a wider regional war that would invariably include Israel’s ally the United States”.