Military Anti-Drone Testing Caused El Paso Airport Shutdown, Sources Say

An airspace restriction that shut down El Paso International Airport on Wednesday was caused by U.S. military technology testing, according to four sources familiar with the matter.

The Department of Defense was testing anti-drone technology near the airport, with the testing taking place close to Fort Bliss. Three of the sources said the military was using high-energy lasers designed to protect against drones from drug cartels that could cross the U.S.-Mexico border. During the tests, the weapons shot down objects later identified as party balloons. The Federal Aviation Administration issued a temporary flight restriction notice in response.

Lawmakers at a National Transportation Safety Board hearing in Washington on Thursday called for answers about the incident.

"We can get into this kind of conflict where the FAA is saying that we're going to shut down airspace for 10 days, and another agency is saying something different, and there's concern about what is happening in the airspace," said Sen. Maria Cantwell (D-Wash.). "Seems to me that we have a real problem of coordination between DOD and FAA. We need to resolve that."

A Trump administration official earlier told NBC News that Mexican cartel drones had breached American airspace and the Defense Department had disabled them. However, the Pentagon has not confirmed that any drones were actually shot down.