A man has been arrested on suspicion of murdering a man who was stabbed while trying to defuse a fight.
Zakaria Bukar Sharif Ali, 26, was attacked outside the Rolling Stock bar in Hackney, east London, in November.
A 35-year-old man has been arrested on suspicion of murder and violent disorder.
A 18-year-old woman had previously been arrested on suspicion of assisting an offender but was bailed pending further inquiries.
There were 132 murders in London in 2018, the highest rate for a decade.