An AirAsia flight with 162 people on board lost contact with air traffic control on Sunday after the pilots asked to change course to avoid bad weather during a flight from the Indonesian city of Surabaya to Singapore, Indonesian officials said.
Indonesia AirAsia Flight QZ 8501, an Airbus 320-200, lost contact with the Jakarta air traffic control tower at 6:17 a.m. (6.17 p.m. EST), officials said.
"The aircraft was on the submitted flight plan route and was requesting deviation due to enroute weather before communication with the aircraft was lost while it was still under the control of the Indonesian air traffic control," the airline said in a statement.
No distress signal had been sent, said Joko Muryo Atmodjo, air transportation director at the Indonesian Transport Ministry.
A search and rescue operation had been launched, the airline and the Indonesian air force said. Singapore said it had activated its air force and navy to help.
Indonesia AirAsia is 49 percent owned by Malaysian-based AirAsia.
The aircraft was between the Indonesian port of Tanjung Pandan and the town of Pontianak, in West Kalimantan on Borneo island, when it went missing, Atmodjo told a news conference.
The aircraft had been flying at 32,000 feet and had asked to fly at 38,000 feet to avoid clouds, he said.
Tanjung Pandan is the main town on Belitung island, roughly half-way between Surabaya and Singapore, and Singapore's Channel News Asia television said there was bad weather over the island at the time the plane went missing.
Indonesia AirAsia said there were 155 passengers and seven crew on board. It said 157 people on the flight were Indonesian, with three from South Korea and one each from Singapore and Malaysia.
The plane had been due in Singapore at 8:30 a.m. Singapore time (0030 GMT).
The airline said the captain and first officer were both experienced.
Neither Malaysia's AirAsia nor any of its affiliates in Indonesia, Thailand, the Philippines and India have had any major incidents or crashes.
Tony Fernandes, chief of Malaysia's AirAsia, said on Twitter: "Thanks for all your thoughts and prayers. We must stay strong."
The incident comes at the end of a disastrous year for the region's airlines.
Malaysia's national flag carrier, Malaysia Airlines, lost two aircraft this year.
Flight MH370 went missing on March 8 on a trip from Kuala Lumpur to Beijing with 239 passengers and crew on board and has still not been found.
On July 17, Flight MH17 was shot down over Ukraine, killing all 298 people on board.