PEBBLE BEACH, Calif. -- A runaway golf cart injured five people near the 16th hole at Pebble Beach Golf Links during the second round of the 119th U.S. Open on Friday, according to the California Highway Patrol.

The CHP said a vendor drove the golf cart loaded with boxes to a concession stand near the 16th hole and parked it around 1:20 p.m. ET. When the vendor climbed out, a box fell on the cart's accelerator and caused it to move.

Witnesses said the unoccupied cart drove in large circles until someone jumped on it and knocked the box off.

Five people were injured in the incident, including one with a broken arm, one with a spinal injury and another with minor injuries, according to the CHP. One person was transported to Community Hospital of the Monterey Peninsula, and those with minor injuries were taken to Natividad Medical Center in Salinas, California.

A woman who said she witnessed the accident told Golf.com that she was standing in a line at the concession stand when the cart started moving.

"We were standing in the concession line on the 16th hole when all of a sudden there was a runaway cart and one guy running after it, then a bunch of people running after it," Georgie Salant told Golf.com. "It was actually coming straight for the concession line and then it turned, just on its own, and it didn't stop. It started driving in circles. It ran over like, five people."

The ages of those injured ranged from 25 to 82, the CHP told the Californian, a California-based newspaper.

The USGA released a statement about the incident, but it indicated that only three spectators and the vendor were hurt.

"Unfortunately, during today's second round there was an incident involving a golf cart on the 16th hole that resulted in three spectators and a vendor being injured and requiring medical treatment. We will continue to monitor their conditions," the USGA said.