All flights to and from El Paso International Airport in Texas have been halted for “special security reasons,” the Federal Aviation Administration said early Wednesday.

“No pilots may operate an aircraft in the areas covered by this NOTAM,” the FAA said, using the abbreviation for Notice to Airmen. It listed the reason as “temporary flight restrictions for Special Security Reasons.”

The restriction for the airspace over El Paso and the neighboring community of Santa Teresa, New Mexico came in at 6:30 a.m. UTC, or coordinated universal time (11:30 p.m. ET). It will end at the same time on Feb. 21.

It did not elaborate on why the restrictions had been put in place for El Paso, which borders Mexico and is the the 23rd-most populous city in the nation according to the 2020 census.

But the NOTAM said the airspace was classified as national defense airspace. Deadly force could be used on an aircraft if it is determined that it “poses and imminent security threat,” it said, adding that pilots “may be intercepted, detained and interviewed” by law enforcement and security personnel.

The airport, which handled 3.49 million passengers in the first 11 months of 2025, confirmed the development in a travel advisory issued on social media, saying that all flights “including commercial, cargo and general aviation” were grounded.

“Travelers should contact their airlines to get most up-to-date flight status information,” it added.

Major U.S. airlines, including Southwest, Delta, United and American fly from the airport.

The FAA did not immediately respond to a request for further comment from NBC News.

This is a developing story. Check back for updates.