The jets seemed to have crashed into a mountain in Pyongchang, Gangwon Province, and the Air Force is searching for the three missing pilots aboard the jets. The drill was a daily routine, according to the Air Force.
Yonhap has the same news, with little more detail.
I hope this story has an better ending than appears likely, I really do. Still, I can't resist reminding people that this was one thing you didn't have to worry about at Vancouver's Olympics!