The following statement is posted on its Facebook page and shared via Twitter @airasia as well.
AirAsia Indonesia regrets to confirm that flight QZ8501 from Surabaya to Singapore has lost contact with air traffic control at 07:24hrs this morning.
At the present time we unfortunately have no further information regarding the status of the passengers and crew members on board, but we will keep all parties informed as more information becomes available.
The aircraft was an Airbus A320-200 with the registration number PK-AXC.
At this time, search and rescue operations are in progress and AirAsia is cooperating fully and assisting the rescue service.
AirAsia has established an Emergency Call Centre that is available for family or friends of those who may have been on board the aircraft. The number is: +622129850801.
AirAsia will release further information as soon as it becomes available. Updated information will also be posted on the AirAsia website, www.airasia.com.