Rome: Hundreds of Juventus soccer fans watching the Champions League final in one of Turin's main squares were injured when loud bangs created a panic and mayhem.

About 400 people were being treated for slight injuries, Italian media reported. About five people were seriously hurt, including a seven-year-old boy who was trampled, Sky TG24 reported.

Thousands of fans had gathered to watch the Champions League final in front of a giant screen in San Carlo Square.

During the second half of the match, which local club Juventus went on to lose 1-4 to Real Madrid, video cameras show a sudden rush in the middle of the crowd that caused a surge that flung people against barriers.

Many fans then began to run out of the centre of the square, screaming in fear.

The panic may been started by the explosion of a loud firecracker that was mistaken for a bomb, a Reuters witness said.

Afterwards shoes and bags littered the ground, people were seen limping and searching desperately for friends and relatives, the witness said.

Police have set up an information point to help people find their loved ones, and they are investigating what caused the panic.

Reuters