Police were called to reports of a stabbing on the South Bank near the London Eye shortly after 11.40pm on Friday night.
Police and ambulance crews attended and a 19-year-old man was taken to hospital for treatment to a stab injury.
Around 20 minutes later, police officers were made aware of a second victim with a stab injury in the South Bank area. The 17-year-old male was taken to hospital for treatment.
At about 3.40am on Saturday, a 25-year-old man presented at hospital with a stab injury.
All three males are believed to have sustained injuries in the same incident. The conditions of all three are described as not life-threatening or life-changing.
Detectives from the Met's Central South CID are investigating. Officers have recovered two knives which were hidden near to the scene and have identified CCTV footage from the area which is being analysed.
Six males have been arrested on suspicion of grievous bodily harm. They all remain in police custody.
Anyone with information that may assist the investigation – or any witnesses or anybody who may have captured relevant images or footage – is asked to call 101 ref 9149/16Jul.