A man says there was "carnage everywhere" after a fatal explosion at a music venue in northern England left around 30 people, including children and other victims, lying on the floor.

There is no confirmed number of deaths yet, but the BBC has reported it is in the double figures.

The man, named as Andy, was waiting to pick up his wife and daughter at the end of Ariana Grande's show when he was blown "about 30 foot" by a blast that shook the building and surrounding areas on Monday night.

He's told the BBC panic then erupted as families rushed to find loved ones amid the chaos.

"It's shocking what happened. Just carnage everywhere. There was a good 20 to 30 of them (victims). Some were young kids, some were disabled people," Andy said.

Emergency services were treating the wounded who were scatted by the blast near a box office at the venue.

"As I was waiting an explosion went off and it threw me through the first set of doors about 30 foot to the next set of doors.

"When I got up and looked around there was about 30 people scattered everywhere, some of them looked dead, they might of been unconscious but there was a lot of fatalities.

"My first thing was to run in the stadium to try and find my wife and daughter.

"When I couldn't find them I looked back outside and the police, fire and ambulance were there and I looked at some of the bodies trying to find my family.

"Luckily they weren't there, I managed to find them outside the arena and got them back to the hotel."