Residents near Royal Air Force Fairford — a British air base used by the United States — were evacuated Sunday morning after a “major incident” involving explosives was declared by local law enforcement, ABC News reported.

“The [counter terrorism] world tracking this story this morning very very closely,” wrote Marc Polymeropoulos, a former CIA intelligence officer, in a social media post on X.

According to ABC News, several people were arrested Sunday “on suspicion of offenses under the explosives act” near the base, which has served as a “key hub for American operations against Iran.” According to The Guardian, a bomb squad was dispatched to the area, and residents of the nearby village of Whelford were evacuated.

“I would like to thank all those emergency and specialist teams who have acted so swiftly regarding the incident in Gloucestershire,” said U.K. Secretary of State for Defense Wes Streeting in a statement. “We can be reassured that this is being dealt with, and it is exactly why our emergency response teams and Armed Forces are on standby 24/7.”

A U.S. Air Force spokesperson declined to discuss specifics about the incident when contacted by The Guardian, but did tell the outlet that U.S. personnel at the air base “remain vigilant” and “take appropriate actions” when necessary to “ensure the safety and security of our U.S. service members, civilians, contractors and their families.”

Iran has previously warned Britain against allowing U.S. bombers to use the air base, including the B-1 Lancer and B-52 Stratofortress, warning that doing so would make the base a “legitimate target.”

“To the British monarchy, which has been the main culprit behind the misfortunes of the people of our region, with a dark record of the dismemberment of Islamic countries, widespread massacres in these nations, the imposition of dictatorial regimes and, worst of all, the organisation and direction of the operations to occupy Palestine and the creation of the Israeli catastrophe, and which has had the greatest involvement in the recent aggressions by the US and the Zionist regime against Iran, we warn it not to add further to its own indictment,” reads a July statement from the Islamic Revolutionary Guard Corps.