A 43-year-old lady and 3 boys, elderly 15, 8 and 4, had been killed in a area hearth in Brent, north-west London.
The emergency products and services have been known as to the blaze in Tillett Close, Stonebridge, at about 01:20 BST.
A 41-year-old guy used to be arrested on the scene on suspicion of homicide and stays in custody, the Met Police mentioned.
An additional two other folks have been taken to clinic, the Met mentioned. Their prerequisites have now not been disclosed. Two terraced three-storey properties have been concerned within the hearth, which used to be introduced below regulate by means of about 03:25, the London Fire Brigade (LFB) mentioned.
Eight hearth engines and about 70 firefighters from stations throughout Wembley, Park Royal and Willesden have been despatched out to take on the blaze.
“A woman and a child were rescued from the second floor of one property by crews wearing breathing apparatus and received immediate emergency care,” the LFB mentioned.
“Both were sadly declared deceased at the scene by a Helicopter Emergency Services (HEMS) team.
“Two extra youngsters have been found out throughout the belongings as crews performed firefighting operations and have been declared deceased on the scene.”
Supt Steve Allen, from the Met’s local policing team in north-west London, said: “This is a particularly tragic incident and our ideas are with everybody concerned… we proceed to paintings along investigators from the London Fire Brigade to ascertain the reason for the fireplace.”
Emergency services will remain in Tillett Close throughout the day as inquiries continue, the Met added.
Leader of Brent Council Muhammed Butt said in a statement: “Our private condolences, ideas and prayers are with the households and buddies of those that misplaced their lives on this horrific incident.
“The council has set up a rest centre nearby and a dedicated team has been looking after families who needed to be evacuated. We will continue to support those affected.
“We are running carefully with the London Fire Brigade and the Metropolitan Police as they behavior their investigations into the reason for the fireplace, and can proceed to supply them our complete reinforce and help.”
Dawn Butler, MP for Brent East, posted on X that she was “devastated to look the deadly hearth” and her prayers have been with the friends and family affected.