Edgewater (United States) (AFP) - A rash of unexplained drone sightings in the skies above New Jersey has left locals rattled and sent US officials scrambling for answers.

Breathless local news reports have amplified the anxious sky-gazing and wild speculation – interspersing blurry, dark clips from social media with irate locals calling for action.

For weeks now, the distinctive blinking lights and whirling rotors of large unmanned aerial vehicles have been spotted across the state west of New York.

But military brass, elected representatives and investigators have been unable to explain the recurring UFO phenomenon.

Sam Lugo, 23, who works in the Club Studio gym in New Jersey’s Bergen county, one of the corners of the state that has seen several drone sightings, called the reports “crazy.”

“It’s pretty concerning they were sighted… without explanation. It can be alarming,” he said.

Officials including the governor have called on people not to be alarmed, but have not yet offered an explanation for the aerial activity.

The clamor for transparency intensified on Thursday when the four senators for New Jersey and New York called on the FBI, Department of Transportation and Homeland Security (DHS) to brief them on how the agencies were working to “identify and address the source of these incursions.”

The White House said the sightings featured in a briefing received by President Joe Biden, while National Security Council spokesman John Kirby said there was “no evidence” of a threat – and that they may be manned aircraft.

“There’s just no indication that this is some sort of foreign, malign activity – or, in fact, even criminal,” Kirby said.

He also called on lawmakers to expand legislation clamping down on drone operations near airports and other high-risk sites.

Later, the FBI and DHS said in a statement that “upon review of available imagery, it appears that many of the reported sightings are actually manned aircraft, operating lawfully. There are no reported or confirmed drone sightings in any restricted air space.”

But social media users have been adamant they have seen outsized drones.

“I’ve seen them every night since Thanksgiving, they’re smaller than my Jeep,” wrote X user Gus Seretis.

“They hover just about tree height or a little higher,” he added, describing them as like aircraft too small for a pilot and vowing to “shoot at one if it comes low enough.”

New Jersey congressman Chris Smith wrote to the Pentagon on Tuesday demanding answers.

“There have been numerous instances of unmanned aerial systems flying over New Jersey, including in close proximity to sensitive sites and critical infrastructure, to include military installations located in my district,” he wrote to Defense Secretary Lloyd Austin.

- ‘Get abducted’? -

Smith said he had been told that more than a dozen drones pursued a coastguard lifeboat over the weekend.

The lawmaker then spent “hours” monitoring the night sky with the sheriff of Ocean County, the location of a number of sightings, according to his office.

The Pentagon, the nerve center of the US military, insists the objects are not “US military drones.”

“Our initial assessment is that this is not the work of a foreign adversary or a foreign entity,” said deputy Pentagon press secretary Sabrina Singh.

Singh also rejected claims by Republican lawmaker Jeff Van Drew on Fox News that Washington’s foe Tehran was behind the spate of sightings.

“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.

New Jersey native Joseph Boutros, 21, said he had seen the reports of drone activity on social media. “But I’ve not seen them myself,” he said.

“It’s not something that worries me as long as they aren’t carrying weapons,” said the suited local as he collected takeout from a Bergen county strip mall as night fell.

In the cloudy skies above, the only aerial vehicles with flashing lights were passenger jets on approach to New Jersey’s Newark airport.

The FBI told AFP it was aware of the sightings “in multiple locations over the past several weeks” and said it was working with other agencies on the issue.

But the agency would not confirm reports of a crisis meeting between various government departments over the mounting concern.

Drones are permitted for both business applications and recreational use but are regulated by Federal Aviation Administration rules.

Witnesses stress that the unexplained aerial objects are larger than those commonly used by drone enthusiasts.

“I don’t want to get abducted or anything like that,” said Lugo with a smile.