A recent alleged plot targeting the RAF Fairford ⁠air base in Britain ⁠was "highly likely" to have been coordinated in Iran, and "almost certainly ​directed" by the Islamic ​Revolutionary Guard ⁠Corps (IRGC), British Prime Minister Andy Burnham said on ​Monday.

The incident near RAF Fairford began in the early hours of Sept. 27 when five British men in their 20s were arrested near the base on suspected terrorism and explosive offences.

They were later released without charge on police bail "under stringent conditions," ⁠and police ⁠said they were considering whether a foreign state had been involved.

Last week, U.S. President Donald Trump said a threat linked to Iran had prompted the removal of American B-1 bombers from the air base, and U.S. ⁠officials have told Reuters that there had been a suspected plot involving Iran to launch ​a drone attack.

"We will not tolerate these ​threats on our soil," Burnham told parliament.

"We will crack down on ⁠Iran's ‌use ‌of criminal networks, using our ⁠full range of powers ‌to target them and their funding streams, ​and we will bring ⁠further sanctions to restrict the ⁠capacity of Iran and the ⁠IRGC to ​do us harm."

Later on Monday, Iran denied any involvement in the incident at the air base, which has been used by the U.S. in its war with the Islamic republic.

"The Iranian ambassador in London, Ali Moussavi, has again categorically rejected the accusations concerning Tehran's role in the incident at the Fairford military base," state news agency IRNA reported, adding that he "called on the British government to present evidence supporting its allegations if it possesses any."