A 22-year-old man has been taken to hospital after a suspected chemical attack at Winter Wonderland.
Officers were called to reports of an altercation between two groups at Hyde Park at around 8pm on December 15.
It was alleged that a bottle containing an alkaline liquid was thrown.
A man was found having been splashed by the liquid and he was taken to hospital for treatment.
His injuries were assessed as non-life changing and no other injuries were reported.
An investigation was launched and three people, two men, 21 and 18, and a 16-year-old boy, were arrested on suspicion of causing grievous bodily harm.
The 16-year-old has been bailed to return to a police station on a date in February.
The two men remain in custody.
A spokesperson for Metropolitan Police said: “Police responded to a report of an altercation involving two groups at Winter Wonderland at approximately 8pm on Sunday, 15 December.
“It was alleged that a bottle containing an alkaline liquid was thrown.
“A 22-year-old man who was splashed by the liquid was taken to hospital where his injuries were assessed as non-life changing.
“No other injuries were reported.
“An investigation was launched and three people – two men, aged 21 and 18, and a 16-year-old boy, were arrested on suspicion of causing grievous bodily harm.
“The 16-year-old has been bailed to return to a police station on a date in February. The two men remain in custody.
“Anyone with information about this incident is asked to call the police on 101 giving the reference 5850/15DEC.
“Alternatively, information can be provided to the independent charity Crimestoppers, anonymously, on 0800 555 111.”