Iran's Islamic Revolutionary Guard Corps warned Britain against further involvement in the US campaign, saying any base used for attacks on Iranian territory was a legitimate target, in a statement issued on July 23.

The warning follows the movement of US strike operations to British soil, after Prime Minister Keir Starmer authorised American use of UK bases on March 1 for what he described as a specific and limited defensive purpose. RAF Fairford in Gloucestershire is the US Air Force's only dedicated forward operating location for heavy bombers in Europe, and hosted 15 B-1B Lancers and six B-52H Stratofortresses at the peak of the March deployment.

The IRGC said US forces had turned to B-1 aircraft flying from Fairford after exhausting cruise missile stocks aboard vessels in the Indian Ocean. A B-1B departed Fairford on a strike mission against Iran overnight on July 22, according to flight tracking data.

"Any base used for aggression against Iranian soil is a legitimate target for us," the statement said, citing earlier foreign ministry remarks.

The force accused Britain of the greatest participation in recent US and Israeli operations against Iran, and of a record of partitioning Muslim countries and organising the occupation of Palestine.

The IRGC said its fighters had destroyed a US electronic warfare unit at a base it called al-Udeiri in the 26th wave of what it termed Operation Nasr 2, striking personnel quarters and killing or wounding an unspecified number. It said the base's flight control tower was hit and that operations were continuing. The claims could not be independently verified, and the base's identity is unclear.

The statement said the attack answered a US strike earlier on July 23 on a route used by pilgrims travelling to Karbala for Arbaeen, the Shia commemoration that draws millions to Iraq. There has been no independent confirmation of that strike.

The IRGC said Washington was seeking a pause to replenish fuel and munitions before resuming attacks, and that Iran would not accept what it called deceptive ceasefires. US officials have spoken in recent days of returning to negotiations.