Seven Australians are listed as among the 239 passengers and crew on board the Malaysia Airlines Flight MH730 that authorities said disappeared from radar and failed to reach its destination - Beijing, China.

News Corp Australia has reported on Saturday that flight MH370, using a Boeing 777-200 plane, last contacted air traffic controllers at around 5:40 AM. By that time, the aircraft was estimated over the Vietnam airspace, near the country's capital Ho Chi Minh.

China's Xinhua News Agency has confirmed that MH370 mysteriously dropped all contacts - radar and radio signal - while flying over northern part of Vietnam. The plane was scheduled to land in Beijing at 6:30 AM, local time, following its take off from Kuala Lumpur at 12:21 AM (Malaysian time).

Also, a statement released by the Malaysia Airlines has indicated that all efforts to re-establish contact with the Boeing aircraft were unsuccessful so far. "We deeply regret that we have lost all contacts with flight MH370," the Malaysian national carrier was quoted by Reuters as saying.

The airliner confirmed too that MH370 is carrying 239 people, including 12 crew members. Among the 227 passengers, composed of 14 different nationalities, two are listed as infants. Majority of the travellers on board are Chinese nationals.

According to News Corp, 152 passengers from China are listed on the flight manifesto. The media firm also revealed that seven Australians are aboard MH370.

"It is our understanding there are Australian passengers on board," News Corp reported a Malaysia Airlines representative as saying.

Efforts are now underway to communicate with the next-of-kin of the passengers and crew members, the airline said, adding that "our thoughts and prayers are with all affected passengers and crew and their family members."

In China, local authorities have suggested that "there had been no reports of any aircraft crashing in Chinese waters."

However, the Chinese Foreign Ministry has admitted that the government is "extremely worried," over the matter.

"We are doing all we can to get details. The news is very disturbing. We hope everyone on the plane is safe," China's Foreign Minister Wang Yi was reported by Reuters as saying.

CNN has reported that prior to its disappearance Flight MH370 is mostly on overland route, which should make it easier for the flight crew to make contact as antenna, radar and radio signal would be readily accessible.

Aviation expert Jim Tilmon, a retired pilot, told the U.S.-based news network that Boeing 777 is "about as sophisticated as any commercial airplane could possibly be."

"It doesn't sound very good," Capt. Tilmon added.

Meanwhile, Reuters noted on its report that this would be the second time in a year that a Boeing 777-2000 will figure in a commercial aviation accident, that is if MH370 is found to have crashed.

In the summer of 2013, China's Asiana Airlines, operating the same Boeing 777 unit, crash landed in San Francisco, California. The incident killed three Chinese passengers, mostly youngsters.