A large number of mysterious drones been reported flying over parts of New Jersey in recent weeks and have more recently been spotted over New York City, sparking speculation and concern over who sent them and why.

Bright lights floating or flying in the night sky above New Jersey have captivated residents for nearly a month. Now the sightings, which many observers believe to be drones, have spread throughout the region.

Officials sound alarm over reports of the strange sights—seen over New Jersey, New York, Maryland and Pennsylvania—with one asking for a “limited state of emergency.”