All U.S. bombers deployed to RAF Fairford in England have returned to their home stations in the United States, the Pentagon said Sunday. The base had been used for strikes targeting Iran. The Defense Department said it had withheld confirmation of the aircraft movements for operational security reasons. It did not say when the bombers left or identify a specific reason for their redeployment. The Pentagon said U.S. bomber crews remain ready to conduct operations around the world, including missions launched from and recovered in the continental United States. The departure comes as British authorities investigate suspected security threats near the base. On Thursday, counterterrorism police arrested a 25-year-old British-Iranian man in London on suspicion of preparing terrorist acts. Five U.K. nationals arrested Sept. 27 after reports of suspicious vehicles near RAF Fairford have been released on bail and remain under investigation. The Pentagon’s statement did not say whether the investigations prompted the bomber redeployment.