A U.S. Air Force helicopter made an emergency landing Tuesday in a baseball field in Numazu, Shizuoka Prefecture, but there were no reports of injuries, police said.

The UH-1N helicopter, of the same type as one that made an emergency landing with engine trouble in Yokohama in August, was on a training flight with three crew members, according to police. The helicopter was undamaged.

The helicopter left the Yokota Air Base in western Tokyo at around 10 a.m. and landed on the baseball field some 40 minutes later. The crew said they detected an operating irregularity and decided to land to prevent an accident, the police said.