"The search and rescue operation continues... We are investigating whether the cause of the crash was environmental or mechanical... the aircraft's condition is not ideal. We hope everyone can be safe and we should know the results this afternoon," Hsiung told reporters.

Gen. Shen Yi-ming had earlier been declared missing after an UH-60M Black Hawk helicopter, carrying 13 senior military officials, crash-landed at Tonghou Creek in the nation’s mountainous Wulai District.

As chief of the general staff, Gen. Shen Yi-ming was responsible for overseeing the island's defense against China, which threatens to use military force to annex what it considers its own territory. (ILKHA)