Explained | Drone sightings in New York, New Jersey: All you need to know

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.

Federal authorities investigating the sightings have provided few answers about what the objects are or their origin, leaving residents unsettled and local leaders frustrated.

US officials on Thursday said that they had been unable to corroborate the reported drone sightings and suggested that many of the objects might be manned aircraft, such as airplanes or helicopters.

But assurances from state and federal officials that the sightings do not indicate a threat to residents have done little to allay public concerns. Lawmakers have expressed frustration with the lack of information and are urging the federal government to share more about its investigation.

By Friday, drone sightings had been reported in several states across the region. In New York, Gov. Kathy Hochul said she was investigating the matter with federal law enforcement agencies, as local officials received numerous reports of possible drones flying overhead.

The governor, however, assured the public that there was nothing to fear. "At this time, there's no evidence that these drones pose a public safety or national security threat," Hochul said in a statement on social media.

Friday evening, however, President-elect Donald Trump also weighed in, suggesting that the government was concealing information about the sightings. Otherwise, they should be shot down, he added.

Here's what to know about the flying objects:

What are they?

Pictures and videos of the purported drones show bright objects illuminated against a dark night sky. Some move while others appear to hover in place. Residents and law enforcement officers who have observed the objects say that their lights sometimes go out suddenly, enveloping them in darkness.

Facebook groups and Reddit threads dedicated to the sightings have accumulated thousands of posts. One Facebook group has tens of thousands of members who share videos and swap theories.

On Thursday, the mystery made its way to the White House, where a spokesperson for the National Security Council, John Kirby, said at a news conference that federal investigators had been unable to corroborate reports of any unauthorized drones above New Jersey.

"To the contrary, upon review of available imagery, it appears that many of the reported sightings are actually manned aircraft that are being operated lawfully," Kirby said.

At a press briefing Wednesday, Sabrina Singh, a spokesperson for the Pentagon, said that the reported objects were not drones operated by the US military and that officials did not believe they were "coming from a foreign entity or adversary."

Local officials and residents have expressed their frustration with federal authorities and the little information they've provided publicly so far.

Rep. Chris Smith, R-NJ, said in a statement Friday that the White House's attitude toward the sightings had been "dismissive."

"The Biden administration has an obligation to the American people to figure out and tell us what is going on immediately," Smith added.

When did the sightings start and where are they occurring?

The wave of sightings began in northern New Jersey in mid-November after personnel inside the Picatinny Arsenal, an Army facility in Morris County, spotted what they said was a drone flying near the base. Days later, reports of the sightings began pouring into the New Jersey State Police, according to a letter with Thursday's date that the state's governor, Phil Murphy, sent to President Joe Biden and posted on social media.

The initial sightings were clustered in a few counties in northern New Jersey, but the phenomenon quickly spread across the state, including to coastal areas in the south and to the Philadelphia suburbs.

In early December, drone sightings were also reported in parts of New York City, first along Staten Island's west shore, then in southern Brooklyn near the Verrazzano-Narrows Bridge. On Thursday, sightings were reported in the Bronx and near LaGuardia Airport in Queens.

Residents in parts of upstate New York, Connecticut and Pennsylvania have also reported mysterious sightings at night. On Friday, Larry Hogan, the former governor of Maryland, said on social media that he had seen "what appeared to be dozens of large drones in the sky" above his home in Davidsonville, Maryland.

How are the sightings being investigated?

Kirby said Thursday that federal authorities had conducted a "thorough analysis" of pictures and videos and were using "very sophisticated electronic detection technologies" to try to determine what the objects were.

At a meeting with state lawmakers that day, New Jersey State Police said officers had been using helicopters to try to follow the drones, according to Brian Bergen, a state assembly member who was present. On one occasion, Bergen said, police flew a helicopter over a drone but were unable to track it for long enough to see where it landed.

On Thursday night, Sen. Andy Kim, D-N.J., accompanied local law enforcement officers who were looking into sightings near the Round Valley Reservoir in Hunterdon County.

In a series of social media posts, Kim said he saw several objects in the sky that did not appear on flight tracking software. Sometimes, he said, between five and seven were visible at once, some glowing white while others flashed red and green.

The Sheriff's Office in Ocean County, in central New Jersey, has deployed its own drone unit to try to get close enough to capture images of the flying objects, but have had limited success so far.

What happens next?

Lawmakers in New York and New Jersey have called on the federal government to provide more information about the purported drones.

In his letter to Biden, Murphy thanked the White House for looking into the issue, but added that it had "become apparent that more resources are needed to fully understand what is behind this activity."

Kirby acknowledged at the Thursday news conference that the spate of reports and public concern about the sightings underscored the importance of having systems to detect and deter drones. Such tools should be made available to state and local law enforcement officials, he said.

Josh Gottheimer, a Democratic member of Congress representing parts of northern New Jersey, announced Tuesday that he would introduce legislation to expand federal grants to help make radar systems available to local law enforcement.

"This technology will equip our law enforcement, who are the best in the world, with the resources they need to identify how many drones there are, where they're coming from and where they're going," Gottheimer said in a statement.