More than 650 modern pentathlon athletes have called for the executive board of the sport's governing body to step down after it decided to remove horse riding from the Olympic program, a sports publication said.

The pentathlon body UIPM decided on Thursday to remove horse riding from the 2028 Los Angeles Games after a broad outcry when a German coach punched a horse that refused to jump a fence at this year's Tokyo Games.

The athletes who signed the letter, including current and former Olympic medalists, said the executive board had "undermined 109 years of modern pentathlon" by taking a decision without consulting athletes and member federations, the site Inside the Games reported on Friday.