A man in his 20s was stabbed in London's Hyde Park on Saturday afternoon.
Police were called to the scene at around 4.40pm on Saturday.
The man was taken to hospital and his condition was initially being treated as potentially life-threatening.
However, it has since been deemed they are not life-threatening, though further details are unclear.
A statement from Scotland Yard said: "Police were called at around 1640hrs on Saturday, 20 April, to a fight in the western part of Hyde Park, W1.
"Officers attended along with LAS and found a man suffering a suspected stab injury.
"Detectives from the Central West Command Unit are investigating."
There have been no arrests at this stage.
Enquiries are still underway and the Met could not state whether the incident was connected to the 420 gathering in the park.
Witnesses or anyone with information are asked to call police via 101 quoting reference 5053/apr20.
Alternatively, they can remain anonymous and call Crimestoppers on 0800 555 111.