The aircraft never made it to Chinese airspace as John Sudworth reports from Beijing International Airport
A search is under way in waters between Malaysia and Vietnam after a Malaysia Airlines plane vanished on a flight to Beijing, with 239 people on board.
Malaysia Airlines said in a statement that flight MH370 had disappeared at 02:40 local time on Saturday (18:40 GMT on Friday) after leaving Kuala Lumpur.
It had been expected to land in Beijing at 06:30 (22:30 GMT).
Malaysia’s transport minister said there was no information on wreckage and he urged against speculation.
“We are doing everything in our power to locate the plane. We are doing everything we can to ensure every possible angle has been addressed,” Seri Hishammuddin told reporters in Kuala Lumpur.
“Our hope is that the people understand we are being as transparent as we can, we are giving information as quickly as we can, but we want to make sure information has been verified.”
Malaysia Airlines chief executive Ahmad Jauhari Yahya said the focus was on helping the families of those missing. He said that 80% of the families had been contacted.
The plane went off the radar south of Vietnam, according to a statement on the Vietnamese government website.
Its last known location was off the country’s Ca Mau peninsular although the exact position was not clear, it said.
The Boeing B777-200 aircraft was carrying 227 passengers, including two children, and 12 crew members.
A plane, two helicopters and four vessels have been dispatched by Malaysia to search the seas off its east coast in the South China Sea, the Malaysian Maritime Enforcement Agency was quoted as saying by AFP news agency.
Vietnam also launched a search while the Philippines said it was sending three navy patrol boats and a surveillance plane, AFP adds, and China sent two ships.
The passengers were of 14 different nationalities, Mr Jauhari said.
Among them were 152 Chinese nationals, 38 Malaysians, 12 people from Indonesia and six from Australia. BBC