A computer glitch at a California air traffic control center disrupted flights in the United States for about an hour Wednesday, authorities said.
Shortly after 2100 GMT, the US Federal Aviation Administration ordered the halting of departures from and to the Los Angeles International Airport (LAX) and all other airports in southern California.
"The FAA's Los Angeles Center air traffic control facility experienced technical issues and stopped accepting additional flights into the airspace managed by the facility for about an hour," the FAA said in a statement.
"Some flights were diverted and the agency issued a nationwide groundstop for flights heading into the airspace managed by the center."
The groundstop was lifted shortly before 2230 GMT but significant delays were expected to last for some time, especially in Los Angeles and San Diego.
Roughly 10 aircraft bound for Los Angeles were rerouted, airport authorities said, while about 30 planes were kept from taking off due to the technical issue.
Some passengers already on board grounded flights were allowed to disembark while the problem was taken care of.
LAX is the third busiest airport in the United States and hosted more than 66 million passengers in 2013, according to official figures.
Some East Coast airports such as Washington's Dulles International also saw delays Wednesday due to wet weather.
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