A Venezuelan army helicopter crashed Friday at a Caracas military base, injuring two crew members but leaving passengers - including the commander of the National Guard - unharmed, a military official said. The Russian-made MI-17 helicopter crashed near a heliport inside Fort Tiuna, a military base in Caracas, a Defense Ministry spokeswoman told The Associated Press. She spoke on condition of anonymity because she was not authorized to give her name. The pilot and co-pilot were injured, but other high-ranking officials on board were unhurt, including National Guard commander Gen. Fredys Alonzo, the spokeswoman said. Authorities are investigating what caused the Friday afternoon crash, she added. It was unclear from what height the helicopter fell.