Since mid-November, large drones of uncertain origin have been repeatedly spotted in the sky at night over central and northern New Jersey.

The drones "operate in a coordinated manner" and have not been identified as hobbyist drones or ones related to the Department of Homeland Security, one official said.

There have been "multiple" instances of drones entering the airspace at a Navy weapons station in New Jersey, officials said, as concern continues to grow over sightings.

Citizens and lawmakers are demanding government answers regarding drone sightings over New Jersey in recent weeks. Here's what to know.

In a letter sent to New Jersey Gov. Phil Murphy, the mayors of 21 towns are demanding action on the mysterious drones spotted flying overhead in recent weeks.

A New Jersey state senator is calling for a limited state of emergency over the mysterious drones that have been seen flying over New York and Jersey.

The U.S. military released dramatic video of Russian fighter jets "harassing" three American military drones in eastern Syria, officials said

The Colorado Department of Public Safety says it is scaling back its investigation into reports of unexplained drone sightings.

The string of mysterious drone sightings in Colorado continues as an emergency helicopter reports it was almost hit by one.

So far, a search has uncovered zero evidence of suspicious activity.

The plane, intended for use in wildfires, carries sophisticated cameras.

Drone sightings in Colorado and Nebraska have so far been unexplained.

The first sighting was on Dec. 17.

It used to be that police departments needed to have a helicopter to locate fleeing suspects from the air -- but drone technology is changing that.

The U.S. Department of Transportation and the Federal Aviation Administration gave the green light for UPS to start delivering packages via drones.

Two reports of a drone seen flying about 3,500 feet above Teterboro Airport in Bergen County, New Jersey, caused a ground stop at Newark Airport, according to the FAA.

Alden Blair told ABC station KABC-TV that the moment was like his late grandmother talking to him on her birthday.

Federal officials this week warned police around the country that drones are posing an ever-growing threat to safety and security.

The Defense Department has issued new guidance to its combatant commands, services and military installations about how to handle drones.

The three were uninjured but "very excited to see rescuers."

Organizers and pilots are working to make it the next great international sport.

Muhammed al-Qawli says a U.S. drone strike killed his brother and his cousin.

The Obama Administration has announced its estimate of civilians killed by drones in Pakistan, Yemen and Africa.

They cannot deliver packages yet.