Detectives continue to appeal for witnesses and information after two men were shot in Forest Gate on May 12.
Police were called that day to reports of shots heard in the Anna Neagle Close, E7 area.
Officers attended and found two men suffering gun shot wounds.
Both men - aged 21 and 22 - were taken to hospital. Neither has life threatening injuries, but both have conditions described as serious but stable.
Trident and Area Crime Command detectives are investigating.
A suspect discharged a firearm at a group of men which included the two victims. The suspect left the scene in a vehicle heading along Capel Road.
Detectives believe the area would have been fairly busy and are appealing for anyone who was in and around the area, that may have seen or heard anything, to contact them.
Any witnesses or anyone with any information are urged to Detective Sergeant Steve Ramshaw on 020 8217 7365 or via 101, to give information anonymously contact Crimestoppers anonymously on 0800 555 111 or at crimestoppers-uk.org.
Four men - aged 19, 25, 23 and 21 - were initially arrested on suspicion of attempted murder.
A subsequent search of an address in connection with the investigation recovered a shotgun.
A male at the address, believed aged 17, was arrested, and 'A' was further arrested, on suspicion of possession of a firearm.
The 19-year-old has since been charged in relation to possession of a firearm.
The other four have been bailed pending further enquiries to dates in early June.