By Joseph Ax

PRINCETON, New Jersey (Reuters) – For weeks, residents of New Jersey and other U.S. states have reported seeing thousands of unidentified lighted drones flying overhead, a phenomenon that has sparked conspiracy theories and prompted lawmakers to demand the Biden administration explain what was behind the mysterious sightings.

U.S. officials have said that most of the sightings involve manned aircraft and that there is no evidence of any threat to public safety or national security. But those responses have done little to reassure anxious Americans or placate state and local officials.

Here is what we know so far.

WHAT ARE PEOPLE SEEING, AND WHERE?

Since November, hundreds of people have shared videos and photos online of bright objects in the night sky. While the majority of incidents have come in New Jersey, people in other states, including Maryland, Virginia, Massachusetts and New York, have reported seeing what appear to be drones as well.

An official told reporters on Saturday that there had been more than 5,000 reported sightings, but that fewer than 100 merited further investigation.

Former Maryland Governor Larry Hogan posted a video of purported drones above his home in Davidsonville, Maryland, though some social media users responded that at least some of the lights in his video appeared to be stars in the constellation Orion.

The sightings have created a social media frenzy. A Facebook group entitled “New Jersey Mystery Drones – let’s solve it” had nearly 75,000 members as of Monday, with people posting theories ranging from extraterrestrials to foreign actors.

WHAT HAS THE BIDEN ADMINISTRATION SAID?

Officials from the White House, FBI and the Department of Homeland Security have all asserted that the objects pose no threat.

In a Saturday media briefing organized by the Biden administration, an FBI official told reporters that the agency was working with 50 local, state and federal partners to investigate, and that no evidence pointed to “large-scale” drone activities. Many of the objects have been sighted along regular flight paths, the official added.

Homeland Security Secretary Alejandro Mayorkas said in an ABC News interview on Sunday that there was “no question” New Jersey residents were seeing some drones, though he added that at least some of the sightings were of manned aircraft. He suggested the increased activity could reflect a 2023 change in a Federal Aviation Administration rule to allow nighttime flying of drones.

HOW HAVE OTHER OFFICIALS RESPONDED?

Some state officials, including New York Governor Kathy Hochul, have called on Congress to enact stricter rules for drones while giving states wider authority to combat drone activity.

“This has gone too far,” Hochul said in a statement on Saturday, a day after the runways at a local airport in New York were shut down for an hour due to drones. On Sunday, Hochul posted on X that the federal government was sending a drone detection system to New York.

New Jersey Governor Phil Murphy wrote a letter to President Joe Biden on Thursday asking for more federal resources to investigate the phenomenon.

President-elect Donald Trump said on Monday that the U.S. military should tell the American public about the nature of the drone sightings. “The government knows what is happening,” Trump told a press conference. “For some reason, they don’t want to comment. And I think they’d be better off saying what it is our military knows and our president knows.”

WHO IS RESPONSIBLE?

It’s not clear. Officials have said most of the sightings were of manned aircraft, but local, state and federal authorities are still investigating.

Some lawmakers have suggested that foreign countries could be dispatching the drones.

U.S. Representative Chris Smith told Fox News that a Coast Guard vessel off the New Jersey shore was trailed closely by more than a dozen drones and speculated that a foreign power could be behind the activity. He said he has asked the military to authorize the shooting down of a drone to learn more.

Another congressman from New Jersey, Jeff Van Drew, said in a statement last week that drones had been spotted hovering near a nuclear plant and suggested an Iranian “mothership” might be responsible for the flying objects. A Defense Department spokesperson said there was no truth to that notion.

Boston police arrested two men on Saturday after a drone was detected “dangerously close” to Logan International Airport, the city’s police department said.

Using drone monitoring technology, police were able to track the operators’ position to a nearby island, where they confronted three individuals who fled on foot. Two of the three were taken into custody and charged with trespassing, with additional charges possible.

(Reporting by Joseph Ax in Princeton, New Jersey; Editing by Frank McGurty and Matthew Lewis)