A police helicopter was heard circling Kilburn after reports of a fight and a man stabbed.
Police were called by the London Ambulance Service to the junction between Allington Road and Kilburn Lane just after midnight (June 5).
There had been reports of a fight and a man stabbed.
Emergency services attended, but the victim had already left the scene.
Officers, assisted by the National Air Police Service, conducted a search of the area but were not able to find the victim.
Enquiries are ongoing to trace both the victim and any suspects.
The incident came less than two hours after a man aged in his 20s was found with knife injuries in Kilburn High Road.
There is no suggestion at this time that the two incidents are linked, but we have contacted Metropolitan Police to confirm this.
Anyone with information about the reported stabbing in Kilburn Lane has been asked to call 101 quoting reference 33/05Jun.
To remain anonymous call the independent charity Crimestoppers on 0800 555 111 or visit crimestoppers-uk.org.
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