London Zoo will be closed "until further notice" following a fire which badly damaged a cafe and shop.
Ten fire engines and 72 firefighters were sent to the zoo at 6.08am after flames broke out at the Adventure cafe.
About three-quarters of the building and half of its roof were ablaze. The fire also spread to a nearby petting area, where goats, sheep, llamas, alpacas, and pigs are housed.
London Fire Brigade said it was not yet known if any animals had been harmed.
Photographs posted on Twitter showed firefighters hosing down roaring flames as smoke billowed from the building. Firefighters battled the blaze for more than three hours before bringing it under control by 9.16am.
Station manager Clive Robinson said: "The fire mainly affected the cafe and shop. Part of nearby animal petting area was also affected although at this stage we don't know if any animals were involved.
"Firefighters worked hard to bring the fire under control as quickly as possible and to stop it from spreading to neighbouring animal enclosures."
He added: "Crews will remain at the scene throughout the morning damping down any remaining pockets of fire."
Crews from Kentish Town, Paddington, Euston, West Hampstead and other surrounding fire stations were sent to the blaze.
The cause of the fire is under investigation.
The zoo will remain closed on Saturday.
It said in a statement: "ZSL London Zoo is currently dealing with an incident on site after a fire broke out. We’d like to reassure you that the fire is now under control.
"The zoo will be closed today until further notice. We will update as quickly as the situation allows."
The zoo, in Regent's Park in the north-west of the capital, is usually open every day except Christmas Day. It is not yet known if it will reopen for Christmas Eve.
