Updated

The U.S. government is restricting drone flights over 133 military facilities for security reasons, marking the first time such flight restrictions have been applied only to drones rather than aircraft in general.

The Federal Aviation Administration said in a statement that it was acting in response to requests from the Defense Department and other security and intelligence agencies. No specific threat was cited.

The FAA's agreement with the Defense Department restricts drone flights to up to 400 feet (120 meters) high within the boundaries of the facilities. The restrictions are effective beginning April 14. Only a few exceptions will be permitted and they must be coordinated with the individual facility or the FAA.

Operators who violate the restrictions could be subject to fines or criminal charges.