The two men shot dead in Ilford early Tuesday morning have been named by police.
Saydi Abu Sheikh, aged 23, and Zakariya Jeilani Mohamed, 32, both from Ilford, died from their wounds after the shooting at a house on Henley Road.
A third man, aged 30, is fighting for life in hospital after the attack. Their families have all been informed.
Police continue to hunt for the suspects in the attack, the sound of which was masked by the explosions of Diwali fireworks.
A schoolboy watching the fireworks reportedly saw a man wearing a Batman-style Joker mask running across his family’s garden shortly after the double shooting, smashing through the fence into a neighbour’s property.
Residents have claimed the killer and his accomplices arrived on push bikes, opened fire and then escaped in a Ford Fiesta just after midnight.
Neighbours had also previously told the Daily Mail that they believed the attack was a “planned hit”.
However, police said they were following a number of lines of enquiry.
“This was an unspeakable act of extreme violence that has devastated two families and sent shock waves throughout the community,” said Detective Chief Inspector Chris Wood.
“My team is working around the clock to identify those responsible and I would like to express my thanks to the people who have already provided information – they can be sure that we will act on everything they have provided.
“We still want to hear from anyone who was inside or near the house in Henley Road when the attack took place.
“The suspects responsible for this horrific act are violent criminals and it is important that they are not protected by a wall of silence –help us take them off your streets by telling us who they are.”
A car linked to the shooting was recovered nearby in Ronnie Lane.
Shama Ahmad, 50, whose flat is just yards from where the two men were shot, earlier said: “I heard some screaming, shouting, and I was a bit shaken by the screams but this is very common around by this area.
“I just looked from my window upstairs and the police and the helicopter above.
“There was fireworks going right in front of my flat, so with the fireworks the shots weren’t heard at all.
“There was this celebration, Diwali thing going on, and fireworks so you couldn’t hear the shots.”
Anyone with information that can help the investigation is being asked to call 101 or Tweet @MetCC quoting CAD 99/25Oct.
To remain 100% anonymous contact the independent charity Crimestoppers on 0800 555 111 or visit Crimestoppers-uk.org.