New Jersey’s governor has called for Joe Biden to take control of an investigation into the mysterious and frequent appearances of several large drones over his state, as frustration grows over federal officials downplaying the incidents.

Democrat Phil Murphy on Friday released a letter he wrote to the White House to express his “growing concern” after Pentagon and FBI officials suggested involvement of the U.S. military or hostile foreign actors in numerous sightings A dozen districts had ruled out unexplained flying objects above an altitude of around 100 kilometers since mid-November.

“It has become clear that more resources are needed to fully understand what is behind this activity,” he wrote in the letter, which was published on the same day as reports of multiple drones breaching Naval airspace Weapons Station Earle in Monmouth County appeared.

“I respectfully request that you continue to direct the federal agencies involved to work together until they find answers to what is behind the UAS (Unmanned Aircraft Systems) sightings.”

Anger is growing among politicians and law enforcement in New Jersey after reports of drone flights mounted in recent weeks, including nearly 50 on Sunday evening alone, NJ.com reported, and after the White House dismissed them on Thursday, at least mostly, “manned aircraft … are operated lawfully.”

Some reports described car-sized drones flying, sometimes in groups, over sensitive military installations and critical infrastructure such as train stations, reservoirs and power plants. In response, the Federal Aviation Administration (FAA) issued a flight ban on a military installation in Morris County and President-elect Donald Trump’s golf resort in Bedminster.

At the Navy weapons station, ABC News said a spokesman said no direct threat had been identified but that personnel were working closely “with federal and state authorities to ensure the safety of our personnel and operations.”

The White House, the Pentagon and the FBI have all said they cannot fully explain the origins of the drones, but have expressed their belief that there is nothing sinister about them.

“We have no evidence at this time that the reported drone sightings pose a threat to national security or public safety or have any foreign connection,” John Kirby, national security spokesman for the Biden administration, told reporters at a news conference on Thursday .

He said an unspecified number of still images and video footage of the incidents were analyzed using “sophisticated electronic detection technologies” and could not be proven to have involved drones.

“To the contrary, upon reviewing the available images, it appears that many of the reported sightings are actually manned aircraft operating legally,” Kirby said.

“Importantly, there are no reported or confirmed drone sightings in any restricted airspace,” he added, appearing to contradict the account of the intrusion at the Navy weapons station.

A joint statement from the FBI and the Department of Homeland Security said the investigation in New Jersey “has not uncovered any such malicious activity or intent at this time.” However, it noted that “the reported sightings there…highlight the inadequacy of current authorities.”

The sightings in New Jersey have parallels to incidents in Europe in recent weeks that also involved unidentified aircraft and military installations. A U.S. air base in Ramstein, Germany, was reportedly attacked; and several “small unmanned aerial systems” were spotted last month over three British RAF bases used by the US Air Force.

Kirby’s comments, which effectively ruled out foreign involvement, echoed those made by Sabrina Singh, the Pentagon’s deputy press secretary, a day earlier. “Our initial assessment here is that these are not drones or activities emanating from a foreign entity or adversary,” she said.

The administration’s statement, or lack thereof, has not impressed politicians, including Murphy in New Jersey, who has called for more action to protect citizens. Republican Congressman Jeff Van Drew told the House Aviation Subcommittee on Wednesday that he believes the drones could be linked to Iran and warned of a possible threat to national security.

Andy Kim, the Democratic senator from New Jersey, released a video on Friday saying he filmed them on Thursday evening in the company of local police – and that the objects had not shown up on a regular flight tracker.

The sightings also extended far beyond New Jersey. Larry Hogan, the Republican former governor of Maryland, said in a tweet on Friday that he “personally saw and filmed what appeared to be dozens of large drones” over his home in Davidsonville on Thursday evening, adding that the incident lasted about 45 minutes took.

“Like many who have observed these drones, I do not know whether this increasing activity over our skies poses a threat to public safety or national security. But the public is increasingly concerned and frustrated by the federal government’s complete lack of transparency and dismissive attitude,” he wrote.

“The government has the ability to track these from their point of origin but has been negligent in their response. People are rightly screaming for answers but are not getting them.”

Drone activity also occurred in some areas of New York. In a tweet posted around noon on Friday, Kathy Hochul, the state’s Democratic governor, reiterated the administration’s statement that there was “no evidence that these drones pose a threat to public safety or national security.” and said state officials were working with partners such as the FBI and Department of Homeland Security “to protect New Yorkers.”

Republican New York politicians, meanwhile, were not so tolerant. Staten Island Borough President Vito Fossella condemned the federal response at a news conference Thursday afternoon.

“What if there were 3,000 reports of sightings of drones or manned aircraft over the U.S. Capitol, the White House or the State House in Albany? There would be an immediate and intensive response to find out what they were and solve the problem,” he said.

“Millions of people here get nothing other than, ‘Don’t believe what you see.'” The post-9/11 saying that if you see something you should say something has become: “If you see something, Don’t worry about it.”

“The people of this city, this state and this region deserve answers about what the hell is going on.”