A Mazda Motor Corp. sport utility vehicle equipped with an automatic braking system crashed Sunday in Saitama Prefecture during a dealership test drive, injuring the driver and front-seat passenger, police said.

The Mazda CX-5 was being driven by a prospective buyer on the dealership's parking lot when it crashed through a urethane barrier set up to demonstrate the SUV's automatic braking feature, according to the Saitama Prefectural Police, which is investigating the accident.

The customer suffered a neck injury while the dealership employee sitting in the front passenger seat fractured his arm, the police said.

Mazda is investigating the case and will cooperate with police if asked to, Makoto Watanabe, a spokesman for the Hiroshima-based automaker, said by phone Tuesday. The company can't comment on whether there have been previous cases where the auto-brake system for the CX-5 didn't work, he said.

"For any safety function, it's impossible to be 100 percent free of accidents," said Hiroshi Ataka, a Tokyo-based auto parts analyst at IHS Automotive. "These technical functions aren't always the easiest to understand."

Mazda's system, called Smart City Brake Support, uses a laser sensor to detect obstacles in front of the vehicle and automatically applies the brakes.