A huge fire broke out at a luxury hotel in central London a week after "the most extensive restoration in its 115-year history" was completed.
Plumes of smoke were seen rising from the five-star Mandarin Oriental in Knightsbridge just before 16:00 BST.
A total of 36 hotel guests and 250 members of hotel staff were evacuated - singer Robbie Williams was among them.
The blaze reached several floors but was quickly extinguished, the London Fire Brigade (LFB) said.
At the height of the fire about 120 firefighters and 20 engines were sent to the the 12-storey building in William Street, near Hyde Park.
The cause of the fire is not yet known and firefighters are likely to remain at the scene through the night, a LFB spokesperson said.
Both the ambulance service and the Met Police attended, although there were no reports of any injuries.
'Billows and billows'
Robbie Williams, 44, described the drama: "I went on the balcony and looked up and there was just billows and billows of smoke.
"I came back in from the balcony and said, 'The hotel's on fire,' and then the next thing a knock at the door came and there was a bellboy there and they said, 'Get out'."
Williams and his wife Ayda Field, 39, ran down an external fire escape to safety.
One hotel worker, who asked not to be named, said: "The fire alarm started and everybody was told to get outside.
"Everything's fine but we don't know how it started yet."
Penelope Evans, 50, from Battersea, south London, was shopping in Harrods when she noticed the thick smoke.
"I saw all this black smoke coming from the sky, it was covering everything and the smell was horrendous," she said.
Ms Evans added: "It was like people were in shock, everyone immediately just started leaving the street and the area.
"There were hundreds of fire engines, ambulances, police racing by and helicopters overhead.
"After Grenfell, I feel like people are a lot more on edge about these things, people just wanted to get out."
Tourist Eric Bantug, who is visiting from Las Vegas, spoke of his shock at seeing a historic building in flames.
The 47-year-old financial services worker, said: "I was just coming up from the Tube and smelled the fire. I could smell burning.
"When I got up above ground I saw all the smoke coming out of the building.
"It's pretty old and it's a shame to see it happen."
The fire in London is the mandarin oriental hotel in Knightsbridge pic.twitter.com/tMrVTOUF3j— Jack (@jackwmartin_) June 6, 2018
Bosses of the international hotel chain recently announced the end of renovation work "designed to confirm this historic hotel's position as one of the best in the world".
Knightsbridge was closed between Sloane Street and Grosvenor Place and a number of nearby buildings, including high-end department store Harvey Nichols, were also evacuated.
Patients and staff were evacuated from the W One cosmetic clinic next door to the hotel, according to Dr Terry Loong who said she and her team were ordered to leave the premises at about 16:00.
Princess Anne had been scheduled to attend a 50th Anniversary Dinner of the Blues and Royals Club at the hotel.
The Mandarin Oriental has previously been used by the Royal Family, including an event for British and foreign royals hosted by the Queen on the eve of Prince William's wedding in 2011.