This is the they're off moment a motorcyclist is felled when she is hit by a runaway horse in a bizarre traffic shunt.

Street cam footage from Necochea, eastern Argentina, on 26th May shows the biker slowing as she reaches a zebra crossing in the city centre.

Then without warning a riderless horse races over the crossing barging straight into the motorbike and gallops away without even slowing down.

The 32-year-old biker, not named in local media, falls to the tarmac as the bike topples over and manages to get up into a squat before passersby rush to help and the clip ends.

The motorcyclist was rushed to Emilio Ferreyra Hospital where she is being treated for injuries to both legs, her right arm and her back.

The horse, which was wearing a New Zealand turnout rug, was later captured by Civil Defence staff but its medical condition is unknown.

Police are trying to track down the animal's owner, who may be liable for criminal charges and damages for negligently failing to control an animal.

City Hall officials have called for stricter animal control rules in urban areas.

(MJ Leidig/newsX)