"It's terrifying to think something like this could happen with so many people in town.

"It was very scary after what happened at the Ariana Grande concert."

A manager at the Viva Brazil bar and restaurant, who didn't want to be named, said: "There was a big police presence outside but it was all over very quickly.

"Thankfully no one was hurt. I wouldn't like to say anymore because it's obviously an ongoing police matter."

A spokeswoman for South Wales Police said two men were arrested following a "motoring dispute".