A British businessman and his two-year-old daughter are thought to be among 162 people missing on a plane in South East Asia.
Hull-born Chi Man Choi and his daughter Zoe are understood to be on board the AirAsia flight which vanished while on a two-hour flight from the Indonesian city of Surabaya to Singapore.
His Singaporean wife and their other child had travelled back to Singapore on an earlier flight, according to Channel News Asia.
Indonesian Transport Ministry official Hadi Mustofa said Flight QZ8501 stopped communicating with Jakarta air traffic control at 7.24am local time (12.24am UK time).
He said the A320-200 had asked to change route because of bad weather before contact was lost.
The flight was expected to arrive in Singapore at 8.30am local time (12.30am UK time).
The search for the plane has been called off for the day, and is due to resume at first light.
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An AirAsia statement said there are 155 passengers on board; 137 adults, 17 children and one infant. Also on board are two pilots and five crew members.
The captain has a total of 20,537 flying hours experience, the first officer has 2,275 flying hours, it said.
Most of those on board - 155 - are from Indonesia, three from South Korea, and one each from the UK, Malaysia, France and Singapore.
According to air traffic control website Flight Radar , the aircraft was travelling at 32,000ft over the Java Sea when contact was lost.
Pilot Rakam Singh told Sky News: "As you climb higher the temperature gets lower ... if you hit turbulence you've got more chance of stalling an aircraft if you hit this kind of weather."
He said the chances of carrying out a safe landing after that were low.
This year has been the worst year for aviation accidents in a decade - largely as a result of the MH17 and MH370 disasters.
Sunu Widyatmoko, chief executive of AirAsia Indonesia, said: "We are deeply shocked and saddened by this incident.
"We are co-operating 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."
The airline has set up an emergency call centre for family or friends of those who may have been on board the aircraft.
AirAsia co-founder and QPR football club owner Tony Fernandes, who has flown to Surabaya, said: "The weather conditions were not good, but further than that we don't really want to speculate anything more.
"Obviously there was storm clouds and the pilot had made a request to change altitude.
"That's as far we know, we don't want to speculate as to whether weather was a contributor or not, we really don't know, let's find the aircraft and then we will do the proper investigation."
The incident comes at the end of a difficult year for Malaysia's airlines. National flag carrier Malaysia Airlines lost two aircraft this year.
Flight MH370 went missing on 8 March on a trip from Kuala Lumpur to Beijing with 239 passengers and crew on board.
On 17 July, Flight MH17 was shot down over Ukraine, killing all 298 people on board.
:: Relatives or friends of those aboard the plane can contact the AirAsia hotline on: +62 212 985 0801.