The news of the disappearance of a Malaysia Airlines plane carrying 239 passengers set off heart-wrenching scenes at Beijing international airport where relatives and friends of the passengers frantically tried to get the latest update on the apparent crash.

Hours after news broke that flight MH370 from Kuala Lumpur to Beijing had lost radio contact with air traffic control, the information panel at the Beijing international terminal showed the flight was delayed.

Though Vietnamese navy officials said the plane crashed off Vietnam coast in the South China Sea, the airline authorities denied the reports and insisted the plane was still missing.

As hours passed, distraught relatives of the panssengers, more than 150 of them from China, became agitated over what they termed the lack of information.

"They keep saying there's no information," a person named Zhai Le told Fairfax Media, adding that her friend was on the missing flight.

Chang Ken Fei, a Malaysian, told Reuters: "At first I thought the plane was just delayed as normal, so I came a bit later, I've just been waiting and waiting."

Scenes of distress and mourning were not limited to Beijing.

Hamid Ramlan, a 56-year-old policeman living in Kuala Lumpur told AFP his daughter and son in law were on the flight.

"My wife is crying. Everyone is sad. My house has become a place of mourning. This is Allah's will. We have to accept it. But we will from tonight hold special prayers for Allah's help. I want to see my daughter and her husband who were on the flight to Beijing for a holiday."

The airline said people from 14 different countries were on board the aircraft and it was trying to contact the relatives of the passengers.

China's Xinhua news agency reported the aircraft lost radar contact over Vietnam. It said the aircraft did not enter the Chinese air space.

Malaysia Airlines said flight MH370 lost contact with the Subang Air Traffic Control at 2:40am almost two hours before it was supposed to land in Beijing.

The aircraft had departed from Kuala Lumpur at 12:21am (1621 GMT).

A relative (woman in white) of a passenger onboard Malaysia Airlines flight MH370 cries as she talks on her mobile phone at the Beijing Capital International Airport in Beijing March 8, 2014.
A relative (woman in white) of a passenger onboard Malaysia Airlines flight MH370 cries as she talks on her mobile phone at the Beijing Capital International Airport in Beijing March 8, 2014. Reuters
flight MH370
A relative of a passenger onboard Malaysia Airlines flight MH370 cries at the Beijing Capital International Airport in Beijing March 8, 2014. Reuters
Family members of those onboard the missing Malaysia Airlines flight walk into the waiting area at Kuala Lumpur International Airport in Sepang March 8, 2014.
Family members of those onboard the missing Malaysia Airlines flight walk into the waiting area at Kuala Lumpur International Airport in Sepang March 8, 2014. Reuters
Family members of those onboard the missing Malaysia Airlines flight walk into the waiting area at Kuala Lumpur International Airport in Sepang March 8, 2014.
Family members of those onboard the missing Malaysia Airlines flight walk into the waiting area at Kuala Lumpur International Airport in Sepang March 8, 2014. Reuters
A man takes pictures of a flight information board displaying the Scheduled Time of Arrival (STA) of Malaysia Airlines flight MH370 (top, in red) at the Beijing Capital International Airport in Beijing, March 8, 2014.
A man takes pictures of a flight information board displaying the Scheduled Time of Arrival (STA) of Malaysia Airlines flight MH370 (top, in red) at the Beijing Capital International Airport in Beijing, March 8, 2014. Reuters