Tourists take a ride on a horse-driven carriage on the frozen Bosten Lake in Bohu county, northwest China's Xinjiang Uygur autonomous region during a winter carnival, January 11, 2020. Photo:China News Service

A loose horse found running on a busy main road in the Welsh capital Cardiff was put on a public bus to take it to safety, police said.

Motorists stopped to try to round up the animal after it was spotted in the fast lane on one of the main thoroughfares into the city on Thursday night.

One woman who helped, Harley Stephens, told the BBC: "The police arrived and we were all a bit flummoxed of what to do because we couldn't get a horse box there in time."

Passers-by managed to calm the horse down and it then "happily trotted" onto a Cardiff bus via its disabled ramp, she added.

She accompanied the horse to a nearby park and ride stop for its owner to collect it. 

"He [the horse] was quite chill about it," she told the broadcaster.

"He had a nice little five-minute drive on the bus. It was crazy, even the police officer said, 'I need to take photos as I don't think anyone will believe me.'"

South Wales Police tweeted a picture of the animal on the bus.

"A loose horse on the 'mane' A48 Eastern Ave decided it wanted to 'stirrup' a little trouble but in doing so it risked falling 'foal' of the law. It then decided to alight an @Cardiffbus," reported the overly punny tweet.

Transport company Cardiff Bus confirmed the unusual rescue mission. "Thankfully the bus is back in its stable, but awaiting a clean," it said.