A U.S. senator has called for mysterious drones spotted flying over sensitive areas in New Jersey and other parts of the mid-Atlantic region to be "shot down, if necessary," even as it remains unclear who owns them.

"We should be doing some very urgent intelligence analysis and take them out of the skies, especially if they're flying over airports or military bases," Sen. Richard Blumenthal of Connecticut said Thursday as concerns about the drones spread across Capitol Hill.

People in the New York region are also concerned that the drones may be sharing airspace with commercial airlines, he said, demanding more transparency from the Biden administration.

The White House said there was no evidence there was a national security or public safety threat. White House National Security spokesperson John Kirby said there were no reported sightings in any restricted airspace. He said the U.S. Coast Guard has not uncovered any foreign involvement from coastal vessels.

"Using very sophisticated electronic detection technologies provided by federal authorities, we have not been able to — and neither have state or local law enforcement authorities — corroborate any of the reported visual sightings, " said Kirby. "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."

Iranian 'mothership' claims panned

The FBI has been investigating and has asked residents to share any videos, photos or other information about the drones. On Wednesday, Pentagon spokesperson Sabrina Singh said they are not U.S. military drones.

Singh rejected claims by a U.S. lawmaker that Iran might be launching drones over New Jersey from a "mothership."

"There is no Iranian ship off the coast of the United States and there's no so-called 'mothership' launching drones towards the United States," she said.

Jeff Van Drew, a House member who switched to the Republican Party from the Democrats in 2020, said he had uncovered what appeared to be an Iranian plot.

"What we've uncovered is alarming — drones flying in from the direction of the ocean, possibly linked to a missing Iranian mothership," he said on social media platform X.

Van Drew didn't offer further proof of his assertions in a Fox News interview on Thursday during which he criticized the Pentagon.

"We aren't being told the truth," Van Drew responded Thursday on Fox News. "They are dealing with the American public like we're stupid."

The number of sightings has increased in recent days, though officials say many of the objects seen may have been planes rather than drones. It's probable a single drone has been reported more than once, New Jersey Gov. Phil Murphy said in a regular local radio appearance on Wednesday night.

Murphy said only federal authorities have the authority to shoot down any craft, and he suggested Van Drew was being irresponsible with this comments.

"I'm not sure what he's been watching lately, but he might want to watch the news," said Murphy. "Israel has decapitated Iran, and we have through economic sanctions, I don't think they've got boats off the coast of Iran right now. Let's not fearmonger this." 

Lawmakers frustrated

The worry stems partly from the flying objects initially being spotted near the Picatinny Arsenal, a U.S. military research and manufacturing facility, and over president-elect Donald Trump's golf course in Bedminster.

In a post on the social media platform X, state legislator Dawn Fantasia described the drones as up to six feet (1.8 metres) in diameter and sometimes travelling with their lights switched off.

Drones are legal in New Jersey for recreational and commercial use but are subject to local and Federal Aviation Administration regulations and flight restrictions. Operators must be FAA certified.

Sen. Cory Booker of New Jersey said he was frustrated by the lack of transparency.

"We should know what's going on over our skies," Booker said Thursday.

"It's allowing a lot of potentially misinformation to spread or at least fear," he added.

Fantasia, a Morris County Republican, was among several lawmakers who met with state police and Homeland Security officials to discuss the sightings from the New York City area across New Jersey and westward into parts of Pennsylvania, including over Philadelphia.

Republican Jersey Shore-area congress member Chris Smith said a U.S. Coast Guard commanding officer briefed him on an incident over the weekend in which a dozen drones followed a motorized Coast Guard lifeboat "in close pursuit" near Barnegat Light and Island Beach State Park in Ocean County.