Ugly brawl breaks out at Perth U2 concert

An ugly brawl has overshadowed the final show of U2's tour of Australia in Perth with several men throwing punches in the crowd.

One man was punched unconscious after the fight broke out at Optus Stadium towards the end of the Irish rock group's set last night.

Witnesses say he was unconscious on the ground for up to 20 minutes before being taken away by paramedics.

U2 fan Mark James said he was shocked to see the brawl erupt in front of families, including children.

"He was in a bit of a bad way," he said.

"Lads were just throwing punches everywhere and falling all over the place."

"There were lots of kids there as well and families. They don't need to see stuff like that. That's just not on."

The venue's management has described the brawl as "shocking" and said it will investigate the response of security and health services.

U2 leaves Australia for Singapore to continue the Joshua Tree tour.