Parts of the ceiling of the air traffic control tower at Subang Airport in Selangor collapsed yesterday, causing delays to flights.
A video showed parts of a ceiling falling on top of a worker in a room with computer terminals, with rainwater pouring into the area.
Malaysia Airports did not say what occurred but posted on its Facebook page yesterday evening: "Dear passengers, we regret to inform that the Air Traffic Control (ATC) at Subang Airport (SZB) is currently experiencing a technical error. This has affected several arriving and departing flights at KUL. We advise passengers to remain calm as our team is working closely with the ATC teams at both SZB and KUL.
"Please check with your airline for the latest flight schedule. Stay with us for the next update."
KUL is another name for the Kuala Lumpur International Airport (KLIA). Later, it updated the page to say that operations were back to normal as of 8.35pm yesterday. But complaints in the comments section of the Facebook posting claimed that inbound and outbound flights at KLIA in Sepang and at the second terminal KLIA2 were still delayed.
Some users claimed in their comments that they were seated on their planes for at least two hours, with no movement from the aircraft on the runway.
A government official, who declined to be named, confirmed that sections of the ceiling at Subang ATC had collapsed.
Several flights between Singapore and Malaysia were affected.
A Jetstar Asia spokesman said KL Air Traffic Control advised airlines flying into Kuala Lumpur of delays due to a backlog there. As a result, two Jetstar services between Singapore and Kuala Lumpur were delayed by over two hours.
Seven Scoot flights were also affected, including some flights from Singapore to Kuala Lumpur and Penang.
Netizens took to social media to voice their frustration over the delays. Twitter user Beth Hollahan tweeted that she and other passengers had been "sitting in (Flight) SQ116 for nearly three hours". "Get us in the air or off the plane. Now!!!!!" she wrote.
Singapore Airlines apologised for the delay "due to unforeseen circumstances".
In response to queries from The Straits Times, an SIA spokesman said that two of its flights were affected by the delay.
The spokesman said Singapore Airlines flight SQ116, an Airbus A350 that was scheduled to depart Singapore for Kuala Lumpur at 1645hrs on Friday (Oct 25), "experienced an extended delay on ground at Singapore Changi Airport due to air traffic control issues at Kuala Lumpur".
SQ116 eventually arrived at Kuala Lumpur at 2057hrs.
Flight SQ118 which was scheduled to depart Singapore for Kuala Lumpur at 1845hrs was also delayed, and eventually departed at 2141hrs, the spokesman said.
• Additional reporting by Jean Iau