Two Thai Air Force F-16 fighter planes taking part in a joint military exercise with the U.S. have crashed in northeastern Thailand. The pilots safely ejected from their jets.

Air Vice Marshal Montol Suchookorn says an investigation team has been sent to the scene of Monday morning's crash in Chaiyaphum province. The area is about 220 miles northeast of Bangkok.

He said he was unable to confirm reports the jets had collided.

The planes were taking part in Exercise Cobra Gold, an annual joint Thai-US military exercise in which personnel from Singapore, Japan, Indonesia, South Korea are also taking part.