WASHINGTON (NEXSTAR)-- A flock of drones flying through the night sky over New Jersey is stirring up some lawmakers. "I'm deeply concerned about it. We've had drone incursions not just in New York and New Jersey, but all across the country over the last several years," Sen. Kirsten Gillibrand (D-N.Y.) said. The FBI and other government agencies have been investigating a growing number of sightings since mid-November.  "There's no so-called mothership launching drones towards the United States," Pentagon Press Deputy Secretary Sabrina Singh said. Gillibrand says Congress needs answers. "I've written a letter to the FAA today demanding answers and much more thorough review of drone activity and a plan in place to take these drones down," Gillibrand said. Governor Phil Murphy (D-N.J.) and other officials met to be briefed on the FBI investigation. Sen. Richard Blumenthal (D-Conn.) is urging officials to find the people responsible. "The ones flying these drones ought to be tracked down and held accountable for common sense, public safety," Blumenthal said. Eleven of the confirmed sightings were over a U.S. military research facility.   "They should be kept away from certain spaces, such as our military bases or airports," Blumenthal said. Sen. Josh Hawley (R-Mo.) is furious that federal agencies do not know much about the drones. "Because if it is true, if we really have no idea, then these people are even more incompetent than they thought," Hawley said. White House National Security Advisor John Kirby says there is no indication it is a foreign adversary. "FBI is looking at this. DOJ is looking at this. I know the Department of Defense when it can, when it affects or comes near a military base. They're looking at this," Kirby said.