SEOUL, Jan. 24 (Yonhap) -- Recent satellite imagery revealed military aircraft flight preparations at North Korea's Wonsan-Kalma airfield, according to a U.S. monitoring website Friday.
It is the first flight activity observed in the location on the North's east coast since North Korean leader Kim Jong-un attended a combat flight contest in November last year, according to the website 38 North.
The purpose of the preparations is unclear, but there could be another flight drill in the near future or may be related to military readiness, it said.
The images taken Jan. 17 and 21 show five MiG-21s and two service vehicles in the northern part of the airfield's passenger terminal and eight MiG-21s and three MiG-17s in the south end of the airfield, indicating flight operations were "either pending or underway," 38 North said.
"While most of the aircraft observed represent older-generation North Korean aircraft, the presence of more than 35 aircraft and their activity is unusual at this airfield."