Hong Kong police have fired a gunshot during protests for the first time since demonstrations broke out in June.

In another first, water cannon were deployed against protesters, who had earlier thrown projectiles at police, including bricks and petrol bombs.

Police told local media that the gunshot was fired as a warning to protesters, and that several officers had been taken to hospital as a result of the clashes.

But police Superintendent Leung Kwok-wing did not say where the shots had been aimed.