Detectives have released a series of images showing individuals they wish to speak to in relation to a stabbing in Hyde Park on Tuesday, 1 June.
Police were called to the park at 21:00hrs following reports of an assault and numerous males brandishing machetes.
On arrival, officers found a male, aged 17, who had been stabbed. He was given immediate first aid and taken to a London hospital where he remains in a stable, non-life-threatening condition.
A 17-year-old male has been arrested on suspicion of affray in connection with the incident.
Detective Superintendent Alex Bingley said: "We urge anyone who knows or can identify the men in these pictures to come forward. No piece of information is too small.
"The brazen violence that was witnessed by many people enjoying the sun in Hyde Park was both shocking and unacceptable.
"We appreciate the images and videos that were widely shared following the incident will have caused concern to people in the area and to those who visit the park regularly.
"I want to reassure the public that we are committed to ensuring our parks remain a safe space for everyone to enjoy. We are doing all we can to track down the individuals involved and bring them to justice.
"Visitors to the park will see an increased police presence and if they have concerns I would encourage them to speak to officers."
Information can be provided to the police by calling 101, or to Crimestoppers, anonymously, by calling 0800 555 111 and providing the reference CAD7861/01JUN.
Hard calls save lives. Are you close to someone on the fringes of knife crime? Do the right thing, please give information, 100 per cent anonymously, through the independent charity Crimestoppers. No piece of information about knife crime is insignificant or too small. Any information you give to Crimestoppers can make a difference in reducing knife crime and the harm it causes to families.
Crimestoppers never ask your name and they cannot trace your call, your IP address or the device you use. Fill in their quick online form or call 0800 555 111. It could save a life.