MANILA -- Three Philippine carriers cancelled at least 82 flights on Saturday after Airbus issued a global technical advisory requiring A320 and A321 aircraft to undergo an urgent software upgrade, Acting Transportation Secretary Giovanni Lopez said.

At a news conference, Lopez said the Philippines immediately grounded affected aircraft operated by Philippine Airlines, Cebu Pacific, and AirAsia upon receiving Airbus' notice at around 1 a.m. local time.

The Civil Aviation Authority of the Philippines (CAAP) said 93 planes have been affected as of noon Saturday, including the delay of six international and five domestic flights.

"The decision to ground the planes was a precautionary measure," Lopez said, adding that once the software update is completed, CAAP can clear the aircraft for deployment.

Lopez said several aircraft had already completed the update as of noon Saturday, and authorities expect all affected units to finish the upgrade by Sunday.

Airbus earlier discovered that intense solar radiation could interfere with onboard flight control computers.

The issue is believed to affect around 6,000 A320-family aircraft worldwide. Most planes are expected to resume operations after the quick software fix.

The European manufacturer identified the problem following an investigation into an incident in which an aircraft flying between the United States and Mexico suddenly lost altitude in October.

Lopez assured passengers that safety remains the government's top priority, noting that measures were taken while airlines work to restore normal operations.