More than 50 unlicensed music events and New Year’s Eve parties were broken up by the Met in London overnight for being in breach of tier four rules.
Five people were reported for a possible £10,000 fine for organising large gatherings, while another 217 were issued with fixed penalty notices.
Two men, aged 18 and 19, were found with stab wounds following one party near Edgware Road.
Commander Paul Brogden said: “Our enforcement activity will continue.”
London is currently in tier four meaning people are not allowed to mix with other households indoors or in most outdoor venues, although an individual can meet one other person in an open public space.
Officers were called to a total of 58 illegal gatherings in the capital as people celebrated the start of the New Year.
The events closed by police included one in Alfreds Way, Barking, in which between 70 and 100 people were dispersed, and another in Kemp Road, Chadwell Heath, where the organiser was issued with a £10,000 fine.
Police said four people had also been arrested at a gathering in central London for breaching Covid regulations.
The two stabbed men were found injured in Edgware Road at about 00:30 GMT.
A 17-year-old girl was also found with a head injury after she was hit with a glass bottle. None of those hurt are in a life-threatening condition.
The Met said the attacks were linked to a party in Connaught Street which had earlier been dispersed by police.
One male was arrested on suspicion of common assault, while a woman was held on suspicion of GBH.
Cdr Brogden said “the vast majority of Londoners complied with the Covid regulations”, but officers “did attend a number of calls to parties and unlicensed events across London”.
He added: “We are still dealing with the stark reality of fighting a deadly virus.
“I urge Londoners to continue to keep themselves and their families safe by staying at home.”