One person has died and 28 were injured after the roof at a heavy metal concert in Illinois collapsed during a storm.

Police in Belvidere, about 50 miles west of Chicago, believe a tornado was to blame and described the scene as “absolute chaos”.

It happened as a violent storm system hit the US south and Midwest, causing widespread damage to homes and businesses and killing at least six other people.

Belvedere fire chief Shawn Schadle said there were 260 people at the Apollo Theatre when the collapse happened at about 7.48pm local time on Friday.

He said emergency workers had to deal with downed power lines outside the venue and also had to rescue someone from a lift.

“I was there within a minute before it came down,” Gabrielle Lewellyn told local station WTVO-TV.

“The winds, when I was walking up to the building, it went like from zero to a thousand within five seconds.”

Ms Lewellyn said people at the gig helped rescue victims from the debris.

“They dragged someone out from the rubble and I sat with him and I held his hand and I was (telling him) ‘It’s going to be okay’,” she said. “I didn’t really know much else what to do.”

Another witness told NBC5 Chicago: “Everybody tried to leave the whole venue through the fire door.

“It was a lot of chaos, so I looked around and saw people in the rubble, and tried to help as many people as possible.”

Five of the 28 people hurt sustained severe injuries, authorities said.

It is unclear which – if any – of the bands on Friday night’s bill had started playing when the collapse happened.

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Twister tears through city Little Rock, Arkansas

Morbid Angel said they were “sheltering in place” in the aftermath, while Crypta band member Taina Bergamaschi said on Instagram that all the acts were “safe and sound”.

The roof collapse happened as thunderstorms and tornados caused dozens of injuries and damaged homes in states including Arkansas – where a state of emergency was declared – as well as Iowa and Indiana.

It came a week after tornadoes with winds up to 200mph also flattened parts of Mississippi, killing at least 21 people and destroying many homes.