A customer shopping in Harrods was stabbed on Saturday evening in what is thought to have been an attempted luxury watch robbery.
People who saw the incident in the world-famous Knightsbridge department store described a pool of blood on the floor after the stabbing.
The store was busy with shoppers and tourists at the time of the stabbing, which was believed to have occurred next to the Louis Vuitton section.
A fight break out before a man was slashed across the arm, say witnesses.
Police are now hunting for the knifemen after he fled the store.
The victim is in hospital with injuries that are not thought to be life-threatening.
Harrods department store in London, UK - in pictures
"Police were called at 7.33pm on Saturday to reports of a fight inside the Harrods store in Brompton Road, Knightsbridge,” said a spokesman for the Metropolitan Police.
"Officers attended and found a 29-year-old man with stab/slash wounds."
Ronnie Chopra, 49, from Mayfair, was in the shop with his daughter when the incident happened.
While they did not see it, another customer said there had been an attempted watch robbery, Mr Chopra said.
"When we were leaving the area, there was a pool of blood on the floor and my 13-year-old daughter, Anoushka, sadly walked into it," he said.
"I'm horrified that this occurred inside a shop in London. She was visibly shaken."
There no noticeable signs of the incident when the store opened on Sunday.
There have not been any arrests so far in connection with the stabbing.
