LIVE UPDATES: Following developments on the missing plane

8.30PM: Live updates begin

8.30PM: Malaysian authorities dispatched a plane, two helicopters and four vessels to search seas off its east coast in the South China Sea, said Faridah Shuib, a spokeswoman for the Malaysian Maritime Enforcement Agency.

The Philippines said it was sending three navy patrol boats and a surveillance plane to help efforts.

8.30PM: Australian passengers families have been contacted by Australia embasies and the airline involved.

More soon.