The trainer aircraft crashed near Suoi Dau Lake in Suoi Tan Commune, which is not near populated areas.

"Half the plane was destroyed and two pilots died," said Nguyen Ngoc Khue, chairman of the Suoi Tan Commune People's Committee.

Nguyen Huu Hao, chairman of the Cam Lam District, said the area surrounding the crash site is on fire, which firefighters are trying to put out.

A witness said: "I was at home when I heard a loud explosion. I ran toward it and saw flames and a column of smoke. A pilot with a parachute was lying unconscious about 100 m from the crashed plane."

Military personnel are inspecting the wreckage, which lies scattered. Authorities have cordoned off the site.

The Air Force Officer Training School in Nha Trang Town, the capital of Khanh Hoa, reported losing contact with the trainer aircraft at 9.35 a.m Friday.

The aircraft was later identified as the YAK-52 of Regiment 920 of the school, according to the Ministry of National Defence. 

Captain Le Xuan Truong of the First Squad of the 920 Regiment and Sergeant Dao Van Long were confirmed to be the casualties in the crash. Truong died inside the aircraft, while Long died on the way to the hospital. 

The cause of the crash is being investigated, the defense ministry said. 

Part of the aircraft near the crash site. Photo by Xuan Ngoc.

Several planes crashed in the Dien Khanh – Cam Lam – Cam Ranh area, Khanh Hoa Province, in the past. A YAK-52 crashed in Cam Hiep Nam Commune of Cam Lam District in 2000, killing two pilots. Another YAK-52 also fell in Suoi Cat Commune of Dien Khanh District in 2004, injuring two pilots.

The YAK-52 is a Soviet trainer aircraft manufactured from 1977 to 1998.