Pentagon reportedly allowed US Customs and Border Protection to use an anti-drone leading to El Paso airspace closure

According to two sources speaking on condition of anonymity, the Pentagon allowed US Customs and Border Protection to use an anti-drone laser earlier this week.

They said that was why the US Federal Aviation Administration suddenly closed the airspace over El Paso, Texas, on Wednesday.

The events began as the US Federal Aviation Administration announced it was shutting down all flight traffic over the city on the US-Mexico border for 10 days, stranding some travellers. However, the closure ended up only lasting a few hours.

US President Donald Trump's administration said it stemmed from the FAA and Pentagon working to halt an incursion by Mexican cartel drones, which are not uncommon along the southern border.

One of the sources said a laser was deployed near Fort Bliss without coordinating with the FAA, which decided then to close the airspace to ensure commercial air safety.

Others familiar with the matter said the technology was used despite a meeting scheduled for later this month between the Pentagon and the FAA to discuss the issue.

While the restrictions were short-lived in the city of nearly 700,000 people, it is unusual for an entire airport to shut down even for a short time.

Normal flights resumed after seven arrivals and seven departures were cancelled. Some medical evacuation flights also had to be rerouted.

Democratic Senator Tammy Duckworth of Illinois, a former US Army helicopter pilot who serves on committees focused on aviationand the armed services said the issue was the latest example of "the lack of coordination that's endemic in this Trump administration."