Journalists examine one of the shattered windows on the media bus shot at in Rio.

A bus carrying journalists at the Rio Games has been hit by gunfire on a highway between Olympic venues, witnesses said.

No one was seriously injured in the incident on Tuesday (NZT Wednesday).

The bus was making its way from the Games basketball venue to the main Olympic park when, according to passengers, two shots were heard hitting the vehicle. Windows shattered and flying glass left two people with minor lacerations.

SHANNON STAPLETON/ REUTERS A broken window on an official media bus after it shattered when driving between OIympic venues in Rio.

"We were shot at. I mean we could hear the report of the gun," said Sherryl Michaelson, a retired US air force captain who is working for a basketball publication in Rio.

Violent street crime in Rio has left its mark on South America's first Olympic Games.

On Saturday, a bullet hit the equestrian centre, missing journalists there by just a few feet. That bullet was suspected to have been fired by a gang member trying to shoot down a police blimp or drone, officials said.

SHANNON STAPLETON/ REUTERS Journalist Joanna Moyse takes a tearful seat on the media bus shot at while travelling on a Rio highway.

BUMP GOES A SPEEDING BUS

On Monday (NZT Tuesday), a Rio Olympics media bus, driving above the speed limit, hit a speed bump injuring three reporters travelling inside it, with one being taken to hospital.

A South Korean journalist was taken to hospital for treatment before being released.

"The driver passed a speed bump that was not visible. He was going above the recommended speed limit," Games spokesman Mario Andrada said.

Transportation has been a problem for Games organisers since the start of the Olympics in the traffic-clogged city, with some media buses running late at times, getting lost or not arriving at all, as was the case at the weightlifting arena on Sunday (NZT Monday).