The US military has relocated aerial refueling tankers based at RAF Mildenhall in Suffolk, England to a base in Germany, according to a source familiar with the matter cited by ABC News. The move followed a reported threat from Iran.

Force protection levels at RAF Mildenhall and the nearby RAF Lakenheath were raised to FPCON Charlie, the source said. A US official told ABC News the military takes proactive measures to keep its aircraft, personnel and installations safe.

A US Air Force spokesperson said aircraft rotate between installations for a variety of reasons, and declined to comment further on the movement of assets, citing operations security. The Wall Street Journal was first to report the reason for the move.

The relocation is the second such move at a British base in recent months. In September, an alleged Iranian security threat at RAF Fairford led to the redeployment of B-1 bombers back to the United States in October.

Source: ABC News