“There’s a lot of us who are pretty frustrated right now,” Rep. Jim Himes, D-Conn., the top Democrat on the House Intelligence Committee, said on “Fox News Sunday.”

“’We don’t know’ is not a good enough answer,” he said.

National security officials have said the drones don’t appear to be a sign of foreign interference or a public safety threat. But because they can’t say with certainty who is responsible for the sudden swarms of drones over parts of New Jersey, New York and other eastern parts of the U.S. — or how they can be stopped — has led leaders of both political parties to demand better technology and powers to deal with the drones.

Sen. Chuck Schumer called Sunday for the U.S. Department of Homeland Security to deploy better drone-tracking technology to identify the drones and their operators.

“New Yorkers have tremendous questions about it,” Schumer, the Senate Majority leader, told reporters about the drone sightings. “We are going to get the answers for them.”

The federal government did little to answer those questions in its own media briefings Sunday morning. “There’s no question that people are seeing drones,” U.S. Homeland Security Secretary Alejandro Mayorkas told ABC’s George Stephanopoulos. “But I want to assure the American public that we are on it. We are working in close coordination with state and local authorities.”

Some of the drones reported above parts of New York and New Jersey have turned out to be “manned aircraft that are commonly mistaken for drones,” Mayorkas said. “We know of no foreign involvement with respect to the sightings in the Northeast. And we are vigilant in investigating this matter.”

Last year, federal aviation rules began requiring certain drones to broadcast their remote identification, including the location of their operators. It’s not clear whether that information has been used to determine who is behind the drones plaguing locations over New York and New Jersey. Mayorkas’ office didn’t respond to questions about whether they’ve been able to identify drones using this capability.

Schumer wants the federal government to use a recently declassified radio wave technology in New York and New Jersey. The radio wave detector can be attached to a drone or airplane and can determine whether another flying object is a bird or a drone, read its electronic registration, and follow it back to its landing place. Schumer said state and local authorities do not have the authority to track drones.

On Sunday, New York Gov. Kathy Hochul said federal officials were sending a drone detection system to the state.

“This system will support state and federal law enforcement in their investigations,” Hochul said in a statement. The governor did not immediately provide additional details, including where the system will be deployed.

Dozens of mysterious nighttime flights started last month over parts of New Jersey, raising concerns among residents and officials. Part of the worry stems 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. Drones are legal in New Jersey for recreational and commercial use, but they are subject to local and Federal Aviation Administration regulations and flight restrictions. Operators must be FAA certified.

Drones are now being reported all along the northern East Coast, with suspicious sightings in Connecticut, Massachusetts, Pennsylvania and Virginia, according to news reports.

Some U.S. political leaders, including Trump, have called for much stronger action against these drones, including shooting them down.

Certain agencies within the Department of Homeland Security have the power to “incapacitate” drones, Mayorkas said Sunday. “But we need those authorities expanded,” he said.

A bill before the U.S. Senate would enhance some federal agencies’ authority and give new abilities to local and state agencies to track drones. It would also start a pilot program allowing states and local authorities to disrupt, disable or seize a drone without prior consent of the operator.

“What the drone issue points out are gaps in our agencies, gaps in our authorities between the Department of Homeland Security, local law enforcement, the Defense Department.,” said Rep. Mike Waltz, R-Fla., Trump’s pick to be his national security adviser, speaking on CBS’ “Face the Nation” on Sunday. “Americans are finding it hard to believe we can’t figure out where these are coming from.’’