The incident between several men happened in Ealing High Street at 1.40am yesterday (December 7).
Officers attended and arrested three men on suspicion of affray and assault on an emergency worker.
They have all been bailed pending further investigation.
A woman sustained minor injuries that did not require hospital treatment.
Police are asking anyone with information to call 101, quoting the reference 619/07DEC25.
The investigation continues.
A spokesperson for the Metropolitan Police Service said: “On Sunday, 7 December at 01:40hrs police were called to reports of a fight between several men on High Street, Ealing Broadway.
“Officers attended and arrested three men on suspicion of affray and assault on an emergency worker.
“They have all been bailed pending further investigation.
“A woman sustained minor injuries that did not require hospital treatment.
“Enquiries continue and anyone with information is asked to call 101 quoting CAD 619/07DEC25.”
