Unauthorized drone activity has prompted a security response at an American base in Britain, the U.S. military said Friday.

Security forces at Royal Air Force Base Lakenheath in eastern England have responded to unauthorized drone activity, and the U.S. military is taking "all measures" to keep base installations, aircraft and service members safe, a spokesperson for U.S. European Command said.

The spokesperson, who spoke on condition of anonymity to discuss sensitive military matters, added that no personnel, aircraft or infrastructure have been affected by the activity.