"We have resumed the search for the missing AirAsia plane at 6am (on Monday). We are heading to east Belitung island," said Tatang Zainuddin, deputy operations chief of Indonesia's National Search and Rescue Agency (Basarnas).
Watch: AirAsia Chief Executive Tony Fernandes says missing plane 'never had any problems'
There is an unconfirmed report of a wreckage spotted east of Belitung Island in the Java Sea, 100 miles from where the plane was last tracked.
Prominent South East Asian businessman Fernandes, the owner of English football club Queens Park Rangers, tweeted: "Thank you for all your thoughts and prays. We must stay strong. My only thoughts are with the passengers and my crew.
"We put our hope in the SAR (search and rescue) operation and thank the Indonesia, Singapore and Malaysian governments.
"Our priority is looking after all the next of kin for my staff and passengers. We will do whatever we can. We continue to pass information as it comes.
"I as your group CEO will be there through these hard times. We will go through this terrible ordeal together and I will try to see as many of you."
Upon arriving in Indonesia, he gave a press conference to family and friends of those on board the plane and said the focus should be on the search and the families.
AirAsia flight QZ8501 departed Surabaya, in Indonesia, on Sunday at 5.30am local time, and was scheduled to land at Changi Airport, in Singapore, at 8.30am (Singapore local time).
The scenes of anguish were reminiscent of those in March 2014, when Malaysia Airlines flight MH370 lost contact with air traffic control several hundred miles north of Singapore. No trace of the craft has been found.
The pilot of the plane has been named as Captain Iriyanto, while the co-pilot is believed to be Frenchman Remi Emmanual Plesel. A picture of the pilot has been posted on social media by his daughter Angela Ranastianis. His nephew praised Capt Irianto as "a very caring person".
Hadi Mustofa, an Indonesia Transport Ministry official, confirmed the search had now been suspended due to bad weather and poor visibility.
"We ended because it was getting dark. The weather was also not too good as it was getting really cloudy," he said. "Tomorrow we will begin at 7am, or even earlier than that if the weather is good."
A family including a groom to be and his parents and brother were reportedly among those onboard.
Fox News reports that Alain Oktavianus Siaun and his family were intending to enjoy one last holiday together before he married.
Captain Iriyanto was piloting the missing flight. Photo / Facebook
Relatives of the passengers of AirAsia flight QZ8501 comfort each other at Juanda International Airport in Surabaya, East Java, Indonesia. Photo / AP
His fiancee Louise Sidharta told the Star in Malaysia she was trying to stay positive.
She said: "I heard it on the radio and immediately browsed the Internet and saw the news. My heart knew by then that my fiancé was on that flight.
"We have to stay positive and hope that they (loved ones) could be found soon."
According to Indonesia's Director of Air Transport, Djoko Murjatmodjo, contact with the aircraft was lost between Tanjung Pandan and Pontianak, a trading port city in west Kalimantan about 100 nautical miles south east of Tanjung Pandan.
AirAsia Indonesia announced the flight's disappearance via a statement on Facebook which said: "[It] 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,' it said.
An official from Indonesia's national search and rescue agency in Medan, North Sumatra monitors computer screens during a search efforts for AirAsia flight QZ8501. Photo / AFP
"At this time, search and rescue operations are in progress and AirAsia is cooperating fully and assisting the rescue service.'
It later issued a statement confirming it had set up emergency briefing rooms for family members of the missing passengers at both airports.
Sunu Widyatmoko, chief executive of AirAsia Indonesia, said: "We are deeply shocked and saddened by this incident.
"We are cooperating with the relevant authorities to the fullest extent to determine the cause of this incident. In the meantime, our main priority is keeping the families of our passengers and colleagues informed on the latest developments.
"We will do everything possible to support them as the investigation continues and have already mobilized a support team to help take care of their immediate needs, including accommodation and travel arrangements."
Tatang Zaenudin, deputy of personnel at Basarnas, said that the agency was working to approve flights from Australia to aid with the huge operation to locate the plane, reported The Sun Herald.
AirAsia has changed the colour of its logo from red to grey as a mark of respect to the missing plane.
The aircraft was an Airbus A320-200 with the registration number PK-AXC.
The last communication between QZ8501's pilot and air traffic control was when he requested to increase his altitude due to bad weather.
According to a leaked air traffic control sheet, the plane's speed had dropped to 353 knots, suggesting it was having trouble climbing, perhaps because of severe weather.
Djoko Atmojio, Director General of Aviation, Indonesian Ministry of Transportation said that the plane had contacted Jakarta Air Traffic Control at 6.12am.
"During that contact, the Jakarta Air Traffic Control could still identify the plane on the radar screen," Mr Atmojito said.
A relative of one of the passengers weeps as she waits for the latest news. Photo / AP
"The plane stated that it was trying to avoid cloud and directed the plane to the left of M635 route and asked to go up to altitude 38,00 feet.
"We have not received the ELT (distress) signal so our conclusion so far is the plane lost contact at 6.17am."
The flight was scheduled to take two hours and ten minutes, and the plane lost contact 42 minutes into the flight time.
An A320 pilot writing on the aviation forum Aviation.net said the weather as the Air Asia flight headed north east was "nasty" but he believed that it would not be enough to cause a major structural failure.
"While the weather on the route looks rather nasty, I have always found that the A320 is a really sold aircraft in turbulence," the pilot, writing from Canada, said.
Relatives of those onboard missing AirAsia flight gather at Juanda international airport in East Java, Indonesia. Photo / Getty Images
"I've flown it through bad winter storms, tropical thunderstorms and all sorts of combined weather and I've never felt that the aircraft was being held together on a hope and a prayer."
Indonesian Transport Ministry official Hadi Mustofa said the plane had asked for an unusual route before it lost contact.
