SU-22_Yemen
Air Force personnel stand near a monument of an old version of the Russian-made Sukhoi SU fighter jet at al-Dailami air base in Sanaa, Yemen on March 6, 2013. Two Su-22 fighter jets collided mid-air in Vietnam on Thursday, April 16, 2015. Reuters/Khaled Abdullah

Update as of 8:00 a.m. EDT: Vietnam has launched a search operation to find the two pilots, who were flying separately in two Su-22 jets and went missing after they ejected from the aircraft over the South China Sea during a training mission. Four reserve fuel tanks were located by the search teams from the area where the aircraft lost contact, the defense ministry said, in a statement, according to Reuters. However, it did not say if the two planes had crashed.

"The two pilots jumped out of the planes and parachuted," Nguyen Hung Tan, chief administrator at the provincial committee for floods and storms prevention, told Reuters.

Original story:

Two Sukhoi Su-22 fighter jets crashed after colliding mid-air in central Vietnam on Thursday during a training mission, Xinhua news reported. The two pilots of the jets reportedly ejected but are missing.

The incident, involving the aircraft from Air Division 370, took place in central Binh Thuan province, the VNExpress online newspaper reported.

Vietnam's air force fleet mainly comprises of ageing, Russian-made fighter jets, according to defense industry websites.

This is a developing story.