The fire took place at Burro Canaglia Bar and Resto, an Italian restaurant in the Salamanca district of the Spanish capital on Friday.

Eyewitnesses claimed the fire started after a waiter carried out a flambe - a cooking technique where food is doused in alcohol before being set alight.

The flames from the dish spread to the walls and ceiling, the eyewitness told Spain's El Pais newspaper.

Emergency services said the fire started near the restaurant's entrance and blocked the main escape route for diners.

Spanish police are investigating the cause of the fire.