Fireworks launched into 4th of July crowd

Nine people have been injured when fireworks misfired into a crowd during a 4th of July celebration in the US.

Jennifer Clark was watching the annual "Salute to the USA" display over Nottingham Lake in Avon, Colorado, overnight when two or three fireworks shells spiralled into the crowd.

Screams rang out as the shells hissed and flashed on people's feet, threatening to explode at any second.

"That was a mistake," a man is overheard saying in the video, before urging others to run.

Jane Imber, who was in the crowd at the time, said there were "a lot of people" at the show and it was lucky no one was seriously hurt.

"There was not a lot of room in between groups of people, so when it happened no one could really get up and run," she told NBC News.

"It was so scary."

The accident occurred about 17 minutes into the 23-minute fireworks show, bringing it the event to an abrupt halt.

A spokesman for the city's council blamed a "malfunction" for the incident, which saw nine people treated for minor abrasion burns at the scene.