A U.S. senator is calling for an investigation into the military’s recent use of lasers to take down drones near the Texas-Mexico border.

Sen. Tammy Duckworth, D Illinois, in a Friday letter asked the inspectors general of the departments of Transportation, Defense and Homeland Security to jointly investigate the use of counter drone high-energy laser weapons that led to airspace closures in and around El Paso. Duckworth is the top Democrat on the Senate Aviation, Space, and Innovation subcommittee, which oversees the Federal Aviation Administration.

The events “raise serious questions regarding interagency coordination, notification procedures, aviation safety protocol, and compliance with federal law,” Duckworth wrote in the letter, which was obtained by Reuters.

The FAA shut down air traffic over El Paso for more than seven hours on Feb. 18 after U.S. Customs and Border Protection deployed an anti-laser drone near Fort Bliss without coordinating with the FAA, according to El Paso Matters.

Days later, on Feb. 25, the U.S. military used a laser to shoot down a CBP drone near Fort Hancock, which is west of El Paso. The incident led the FAA to temporarily close airspace around the area.

In her letter, Duckworth asked the inspectors general to review the decision-making process for deploying anti-drone lasers, evaluate risks to commercial airlines and determine whether any federal laws or regulations were broken, The Hill reported.

Earlier this month, the Pentagon and the FAA agreed to conduct anti-drone laser tests in New Mexico as a result of these airspace closures.

This article originally published at U.S. Senator wants investigation into anti-drone lasers that caused El Paso airspace closures.