German authorities warned Wednesday of a growing drone threat as they confirmed that unmanned aerial vehicles feared to be Russian flew over key military and industrial sites last week. Authorities had already revealed that a swarm of drones was spotted over the state late last week. She did not say who was to blame, and added the threat level in the state had not increased. A large “mother” drone was sent off from the vessel and then released a swarm of smaller drones, it said. Dobrindt last week announced that Germany is planning to create a new “drone defence centre” that will pool the expertise of Germany’s federal and state governments.