Police were called to the Phoenix snooker club, Lea Bridge Road, E10 shortly before 3am on Sunday, 7 July to reports of gunshots.
Officers, including firearms officers, attended and found a man, aged in his late 20s, suffering from a gunshot injury. Despite the efforts of officers and the London Ambulance Service (LAS), he was pronounced dead at the scene.
His next of kin have been informed. Formal identification has not yet taken place.
A post-mortem examination will be held in due course. Formal identification awaits.
Two men, aged in their 20s, have been arrested on suspicion of murder, they are currently in police custody. They both suffered non-life threatening injuries during the incident and were treated at an east London hospital.
A crime scene remains in place.
The Homicide and Major Crime Command are leading the investigation.
Detective Chief Inspector Mark Wrigley said: “We understand the victim and two other men went to the snooker club. The victim was then involved in an altercation with another group and a number of shots were fired. A young man has lost his life and two others are injured.
“Were you there? Did you see anything before or after the attack?
“I would appeal to anyone at or in the proximity of the Phoenix snooker Club. Anyone with information about this fatal shooting to contact the incident room. Detectives are ready to take your call.
Chief Superintendent Richard Tucker, said: “I want to reassure the residents and communities of Waltham Forest and Newham, as well as across wider London, who are concerned and alarmed following recent tragic incidents, including the most recent fatal shooting in Leyton in the early hours of Sunday morning; The Metropolitan Police is working with our partners to do all we can to prevent such tragic attacks and are determined day and night to apprehend those involved and take weapons off the streets.
“The shootings in Wembley and Leyton are not being treated as linked. Our local policing teams are working with the Violent Crime Taskforce and other specialist resources, as well as with our local partners to help keep London safe.
“Those near crime scenes can expect an enhanced policing presence in their area in the coming days. Officers will be on hand to listen to any concerns they have and continue to appeal for those with information to come forward.”
Anyone with information is asked contact police via the incident room on 0208 345 3715 or Crimestoppers anonymously via 0800 555 111.