All 132 people onboard a China Eastern Airlines Boeing 737-800 aircraft, which came down in southern China en route from Kunming to Guangzhou, are feared dead.

The Boeing 737-800 is not one of the Max models that were grounded following two fatal crashes that killed 346 people and forced Boeing to make major changes to the aircraft’s software and its training.

India’s aviation regulator has put the 737-800 under "enhanced surveillance", the BBC reports, "to monitor flight procedures, air worthiness and operations".

"Flight safety is serious business, and we are closely studying the situation," the BBC reported Arun Kumar, chief of India’s Directorate General of Civil Association, as saying. "In the interim, we are focusing on enhanced surveillance of our 737 fleet."

Indian carriers SpiceJet, Vistara and Air India Express all have Boeing 737 aircraft in their fleets.

In a statement, Boeing said: "Our thoughts are with the passengers and crew of China Eastern Airlines Flight MU 5735. We are working with our airline customer and are ready to support them.

"Boeing is in contact with the US National Transportation Safety Board and our technical experts are prepared to assist with the investigation led by the Civil Aviation Administration of China."

According to flight data analyst Cirium, there were 4,208 Boeing 737-800 aircraft in service on Monday. Nearly 1,200 of them are based in China.