AirAsia says a flight from Indonesia to Singapore is missing.
Flight number QZ 8501 lost contact with the Jakarta air traffic control tower just after 6am local time.
The AirAsia plane was carrying 162 people, Indonesia's MetroTV station is reporting.
It went missing after takeoff from Indonesia on the way to Singapore.
The plane lost communication with Indonesia's Surabaya airport 42 minutes after takeoff at 5.35am local time, Hadi Mustofa, an official of the transportation ministry told Indonesia's MetroTV.
Mustofa said that the plane lost contact when it was believed to be over the Java Sea between Kalimantan and Java islands.
Initial reports out of Indonesia indicate that no Australians were aboard an AirAsia flight that's lost contact with air traffic control between Indonesia and Singapore.
Indonesia's Metro TV reports there were 149 Indonesians, 3 Koreans, 1 Singaporean, 1 Briton, and 1 Malaysian on board.
A search and rescue operation is underway for the missing flight, the airline says.
The AirAsia plane travelling from Indonesia to Singapore was carrying at least 161 people, Indonesia's MetroTV station is reporting.
The plane lost communication with Indonesia 42 minutes after takeoff, Hadi Mustofa, an official of the transportation ministry told Indonesia's MetroTV.
The Airbus plane left Juanda international airport in Surabaya in east Java at 5.20am local time and was expected to arrive in Singapore at 8.30am (1130 AEDT).
The QZ8501 flight lost contact when it was believed to be over the Java Sea between Kalimantan and Java islands according to Mustofa.
'The AirAsia flight flying from Surabaya to Singapore lost contact with Jakarta at 7.55am (local time),' transport ministry spokesman J.A. Barata told AFP.
Australian media reports cited Indonesian Transport Ministry official Hadi Mustofa as saying the plane had asked for an unusual route before losing contact.
The plane was carrying six crew and 155 passengers - 138 adults, 16 children and a baby, Barata said.
The airline has created an emergency call centre for family or friends who those who may have been on board the aircraft.
Information about those on the flight has been released on pinboards at a crisis centre set up at Surabaya's Juanda Airport.
Indonesian TV showed people in tears after finding their family members' names on the lists.
The aircraft was an Airbus A320-200 with the registration number PK-AXC.
Indonesian Air Force spokesman Hadi Tjahjanto told Metro TV one Boeing 737 surveillance plane had been deployed to the location where it's estimated the plane lost contact.