Three persons were stabbed to death after a clash between two groups within the Sikh community in east London, police said on Monday.
The victims were believed to be in their 20s or 30s, they said.
Police said they received a call about 19:40 GMT on Sunday to reports of a disturbance in Elmstead Road in Seven Kings, Ilford.
"We believe the groups involved are members of the Sikh community," Chief Superintendent Stephen Clayman was quoted as saying by the Telegraph.
Clayman said the suspects and the victims were known to each other.
Two persons have been arrested on suspicion of murder, the officer said.