A man has been arrested after a firefighter was "violently attacked" while attending a flat fire in south London.
Twenty-five firefighters were called to a property in Kensington Avenue, Thornton Heath on Tuesday.
One of the firefighters was struck over the head when entering the flat. He was taken to hospital but has since been discharged.
A 53-year-old man was arrested at the scene. A Taser was used by police.
The arrested man has been held on suspicion of attempted grievous bodily harm, assaulting an emergency worker and arson with intent to endanger life.
He remains in custody.
London Mayor Sadiq Khan said it was "appalling" that a firefighter had been "violently attacked".
"Violence towards our emergency service workers will not be tolerated and those who carry out such attacks must face the full force of the law," he said.
London Fire Brigade (LFB) deputy commissioner Richard Mills said had it not been for his helmet, the firefighter would have sustained serious head injuries.
"This abhorrent and unprovoked attack on a firefighter is completely unacceptable, but during a global pandemic when all emergency services workers are going above and beyond to serve the public it is even more shocking," he said.
The cause of the fire is under investigation by LFB and the Metropolitan Police.