BEIJING, 21 Mar (CNA)- President Xi Jinping called for "all-out" efforts to organise search and rescue for passengers on a China Eastern Airlines plane on Monday (Mar 21), after the jet carrying 132 people crashed into a mountainside in southern China.

Expressing "shock" at hearing the news of the crash, Xi instructed officials to the launch an emergency response immediately and to investigate the cause of the crash as soon as possible, according to state television CCTV.

China's Premier Li Keqiang also instructed officials to spare no effort in searching for survivors and to provide sufficient comfort to the victims' families, according to CCTV.

The Boeing 737 flight from Kunming city to the southern hub of Guangzhou "lost airborne contact over Wuzhou" city in the Guangxi region on Monday afternoon, according to the Civil Aviation Administration of China (CAAC).

Fears for the fate of the jet spread on Monday afternoon as local media reported that China Eastern flight MU5735 had not arrived as planned in Guangzhou after taking off from Kunming shortly after 1pm.

Flight tracking website FlightRadar24 showed no data for the flight after 2.22 pm.

The tracker showed the plane had sharply dropped from an altitude of 29,100 feet to 3,225 feet in the span of three minutes, before flight information stopped.