Reuters: State news agency Xinhua reported radar contact with the flight was lost while it was in Vietnamese airspace.
From AsiaOne:
BEIJING - Radar contact with a Malaysian Airlines aircraft that has gone missing on a flight from Kuala Lumpur to Beijing was lost in airspace controlled by Vietnam in the early hours of Saturday morning, China’s Xinhua news agency said.The aircraft did not enter airspace controlled by China and did not make contact with Chinese controllers, Xinhua added, in a report on one of its official microblogs.
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