The Federal Aviation Administration (FAA) ordered a full ground stop at all West Coast airports on Monday, as North Korea fired what appeared to be a ballistic missile into the Sea of Japan.
The stop lasted for about seven minutes, according to San Diego media, citing radio traffic and officials at the San Diego International Airport.
Sabrina LoPiccolo, spokeswoman for the airport, told Newsweek that the airport was instructed by air traffic of a national ground stop about 2:30 p.m. Pacific time. No reason was given for the stop, which lasted about five to seven minutes, she said.
"We really don't have any more details," she said.
The FAA has not released further details on the ground stop and did not respond to a request for comment from Newsweek Monday evening.
An FAA ground stop is an order that directs flights scheduled to land at the affected airports to stay at their departure point. Ground stops can be specific to an airport or region and can be related to weather, equipment outages or extreme events. Notably, the FAA issued an order following the 9/11 attacks.
A recording of radio traffic at the Hillsboro Airport, outside of Portland, Oregon, from Monday captures ground control advising pilots of a national ground stop and turning them away.
The South Korean and Japanese militaries said North Korea launched the missile early Tuesday morning, making it the second launch by the reclusive country in less than a week.
It's not clear how far the missile flew and details on the launch haven't been released. South Korean and U.S. militaries said they are reviewing the incident. The Offices of Guam Homeland Security and Civil Defense were monitoring reports of the launch but there was no threat for Guam, a U.S. territory that serves an important military hub in the Pacific.
North Korea said it successfully launched a hypersonic missile last week.
Hypersonic weapons fly at speeds in excess of Mach 5, or five times the speed of sound. Their speed makes them difficult for missile defense systems to detect and stop.
But South Korea said the projectile was a ballistic missile and has cast doubts on North Korea having acquired the technology for hypersonic weapons.
The earlier Jan. 5 tests came after Kim Jong-un, North Korea's leader, said during a key political gathering that he would boost the country's military power. Kim had previously engaged in a diplomatic effort with former U.S. President Donald Trump to ease sanctions on the country in exchange for giving up some of its nuclear capabilities.
The Biden administration has said it's willing to resume talks with North Korea without preconditions. But so far, North Korea has rejected the offers, saying the U.S. needs to withdraw sanctions and joint U.S.-South Korea military drills.
This article originally appeared on Newsweek