The strait is quite shallow, 40 to 50 metres in depth, so sonar on Indonesian vessels should be able to be deployed in the search. Mr Fernandes spoke at a news conference in Surabaya on Sunday night, saying the plane's disappearance was "unbelievable" and "a massive shock". "We don't want to speculate but right now, the plane has been missing for 12 hours and there's a deep sense of depression here," he said. Mr Fernandes said the airline did not know any more than the public knew: that the pilot asked for permission to climb to get around a storm and then, shortly afterwards, the plane lost communication with air traffic control and went off the radar.

"That's as far as we know, and we don't want to speculate ... Let's find the aircraft, and then we'll do a proper investigation," he said. Passengers onboard the flight include 138 adults, 16 children and one infant. Also on board were two pilots, including a French co-pilot, and five cabin crew. Australian Prime Minister Tony Abbott spoke with Indonesian President Joko Widodo to express his condolences and offer assistance. He told Mr Joko that Australia had a P3 Orion aircraft on standby ready to assist the search if it was required.

Foreign Affairs Minister Julie Bishop said she understood no Australians were on the plane. "It's always deeply concerning when we hear news such as this and all we can do is ascertain as much as we can about the details of the flight and to determine whether there were any Australians on board," Ms Bishop said. She also added that she had offered Australia's "support and assistance". The missing plane departed at 5.35am Indonesian time (9.35am AEDST) and was scheduled to arrive at 8.30am Singaporean time (11.30am AEDST).

Transport Ministry official Hadi Mustofa said the aircraft lost contact with the Jakarta air traffic control tower early on Sunday morning. AirAsia said this occurred at 7.24am local time (11.24am AEDST). He J.A. Barata, a spokesman for the Ministry of Transportation, said the pilot had asked to go to 38,000 feet to avoid clouds to the left. Just five minutes later, at 6.17am local time, the tower in Jakarta lost contact with the aircraft. At 6.18am it had vanished from the radar. At 7.55am the flight was officially declared missing. When it went missing, the plane still had enough fuel for four hours flying time. As a press conference, Indonesia's Minister for Transport, Ignasius Jonan, said the flight went missing between Tanjung Pandan and Pontianak, and, on the last contact, it was not far from the shoreline.

The search began where the plane went missing and would then get wider. It is expected to resume at 7am Monday morning (local time), or even earlier if the weather was good, Mr Hadi said. Search and rescue agencies were on the move from Singapore and civilian shipping was asked to provide any information if they saw anything. The Minister of Transport asked the media not to make any assumptions, but to be patient, and as soon as they had any information it would be released. They intended to give an hourly update at the airport. Indonesian vice-president Jusuf Kalla announced late on Sunday there was a "high possibility that an accident has happened". "The government is deploying all force: military, search and rescue, and is using all available personnel and equipment to locate the plane, whether it's on land or water," he said.

However, F.H.B. Soelistyo, the head of Indonesia's national search and rescue agency Basarnas, drew attention to the relative weakness in Indonesia's technology, saying the sonar on their boats only reached to a depth of 200 metres. He said a command centre would be set up by 6am on Monday in Pangkal Pinang, on one side of the Karimata Strait, where the plane went missing. Tatang Zaenudin, Basarnas deputy of personnel, said seven ships to search in the sea near Belitung had been deployed however the rescue boats were not expected to arrive at the area until midnight local time. Mr Tatang said two Hercules aircraft had also been cleared to fly from Singapore to the site, and preparations were underway to speed up the process to approve flights from Australia to assist. The local search and rescue chief from Pangkal Pinang, Joni Superiyadi, told Fairfax Media the closest rescue ship was 100 miles from the point where the plane went missing. It would take six to 10 hours at 10 to 15 knots for the boat - the fastest they have - to get there.

Any report of debris found at the scene was false: he had received no notification from any private vessel, he said. A crisis centre has been set up at Surabaya airport and relatives have begun arriving to tearfully view a full list of names of those who were on the flight. Passengers' relatives told airport officials in Surabaya they had been trying the mobile phones of their loved ones without success. Indonesian vice-president Jusuf Kalla tweeted: "We pray together with hope that the AirAsia plane QZ8501 SBY-Sin, which lost contact, is soon found and all passengers and crew have survived." AirAsia chief executive Tony Fernandes tweeted: "Thank you for all your thoughts and prays. We must stay strong,"

One woman at the crisis centre had seven family members including her mother and brother on board the flight. In posts on Facebook and Twitter, AirAsia confirmed the plane had gone missing.

Shortly after the airline posted its first message, it changed its Twitter and Facebook profile pictures, removing its red and white logo and replacing it with a grey and white one. "At this time, search and rescue operations are in progress and AirAsia is cooperating fully and assisting the rescue service," the airline said. "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." AirAsia said the captain in command had a total of 6100 flying hours and the first officer a total of 2275 flying hours.

The aircraft, an Airbus A320-200 with the registration number PK-AXC, had undergone its last scheduled maintenance on November 16. The head of the rescue operation from the Indonesian search and rescue agency said there were three possibilities when a plane lost contact at the height it did: engine failure, that it had ditched over the sea, or was diverted to another airport. The other airports in the region have been contacted, but have no record of a diversion, he said.

AirAsia was embroiled in controversy earlier this year after publishing an article in their in-flight magazine claiming their planes would "never get lost". Travel 3Sixty AirAsia apologised for the article but insisted it was written and published before the disappearance of flight MH370. Loading MH370 went missing in March with 227 passengers on board, and the plane has not yet been found. Malaysia Airlines Flight 17 was shot down in Ukraine on July 17 over area controlled by pro-Russian separatists. All 283 passengers and 15 crew on board were killed. with agencies and staff writers