WASHINGTON — A puzzling flurry of apparent drone sightings along the US east coast is "nothing nefarious", says President Joe Biden.

The sightings in recent weeks have occurred in New Jersey and a number of neighboring states, sometimes around air bases. The phenomenon has prompted a number of conspiracy theories about foreign involvement.

Authorities have not given many definitive answers, other than to say the sightings are not always of drones, and that they do not believe there is a threat to national security or that a foreign power is at work.

Members of the US House Intelligence Committee, who were given a closed-door briefing on Tuesday, joined Biden on Wednesday in trying to reassure the public.

Among the committee members who spoke to reporters afterward were Chrissy Houlahan, a Democrat.

"To date, they haven't found anything that would indicate that there's foreign influence, foreign actors, or even little green men who are working on the American people," she was quoted as saying by The Hill.

Another lawmaker, Connecticut Representative Jim Himes, said "there is zero evidence of laws being broken" by the drones.

He added that the "vast majority" of sightings were normal aircraft or drones being operated lawfully.

Himes said that "millions" of unregistered drones were operating across the US, in addition to 800,000 registered drones that weigh more than half a pound.

In his own comments to the media, Biden said: "We're following this closely, but so far, no sense of danger."

He stressed that the sightings were not evidence of any wrongdoing. "There's a lot of drones authorized up there," he said. "I think one started it and they all – everybody wanted to get in the deal."

On Wednesday, a motion to expedite a federal bill aimed at giving more resources to local law enforcement to identify and neutralize drones failed in the Senate.

The bill required unanimous consent in order to be rushed through. Despite support from New York Senator Chuck Schumer, it was voted down by Kentucky Senator Rand Paul, who had concerns over privacy.

In recent days, the sightings have led to the temporary closures of a Stewart International Airport in New York and of Patterson Air Force Base in Ohio.

Government agencies previously said they had "not identified anything anomalous". They agreed with Biden that many drones that had been sighted were lawfully flown by hobbyists and law enforcement – adding that people were also spotting "manned fixed-wing aircraft, helicopters, and stars mistakenly reported as drones".

But questions from the public remain. Earlier in the week, New Jersey man Noel Thomas described to the BBC his experience of spotting a mystery object in the sky. He said it was the size of a school bus, rectangular with blinking lights, and "definitely something I've never seen". — BBC