Marco Rubio said the incident at the British air base RAF Fairford “clearly involved” a foreign actor, according to The New York Times.

British counterterrorism police said on Tuesday they had found no explosives in the three vans used by the five men arrested on suspicion of planning a terrorist act near a base used by American bombers to strike Iran. The men were detained early Sunday after three vans were spotted near RAF Fairford, a UK-owned base, according to the Associated Press.