Three men were stabbed during a fight in West Drayton on Wednesday afternoon.
Officers were called to the junction of Broadway Junction and Station Road at around 4pm where they "found blood at the scene."
However the Metropolitan Police said they have found no victim or suspects.
Shortly after the altercation, three men presented themselves at a west London hospital with stab injuries that are believed to be not life-threatening or life-changing.
A heavy police presence was reported by eyewitnesses at the scene and a video taken by Twitter user Josh Todd showed blood spattered on the pavement.
A local resident, who did not want to be named, said: "I've just seen blood on the pavement as I drove past.
"Traffic is crazy down there. This one part of the High Street is blocked off."
Photos from the scene show Cherry Orchard blocked off by a police cordon.
Another resident described the scene on the High Street as "manic".
She said: “I was on the bus and got off at the Harlington Hospice charity shop and saw they’d taped off the road.
“I then went and talked to a couple of the girls in the shop. Apparently a car pulled up, some lads jumped out and started hitting these other lads with a baseball bat.
“There was blood everywhere.
“I’ve seen officers now carrying bags, it looks like they’re collecting evidence.”
No arrests have been made and the Met Police is carrying out enquiries.
Anyone with information or any witnesses should contact police on 101 or Tweet @MetCC or contact Crimestoppers anonymously on 0800 555 111 or online at www.crimestoppers-uk.org .