A huge blaze broke out overnight at Camden Lock Market in north London.
London Fire Brigade (LFB) said 70 firefighters and 10 fire engines were sent to the site, which is a popular tourist attraction.
One eyewitness said the fire moved “very fast” and there were fears of an explosion in nearby buildings.
London Ambulance Service said it had not treated any patients but remained at the scene.
The cause of the blaze is unknown.