Met Police announced the fifth killing just over a week as a man in his mid-twenties or early thirties was found with multiple stab wounds in the East End.
He was pronounced dead at the scene in Bethnal Green.
The violent clash is believed to have taken place a former care home which is used by squatters.
Becoming fifth victim in eight days, four of whom have been stabbed.
And it is the sixteenth murder inquiry to be launched by this year by the Met Police.
“A man, thought to be aged in his mid-20s or early 30s, was discovered suffering from stab wounds.”
Bright Akinleye, 22, was fatally stabbed in a street near Euston station before staggering into a hotel lobby where he collapsed and died last Monday night.
The following day 69-year-old Brian Wieland, 69, died in a fire at a house in Chingford, east London.
A woman has been arrested on suspicion of murder.
Glendon Spence, 23, was fatally stabbed at a youth club in Brixton, south London, last Thursday.
A teenager has been charged with murder.
And a 19-year-old, who has not been formally identified, was fatally shot and stabbed in Wood Green, north London, over the weekend.
Police are fighting a knife crime crisis on the streets of London after the number of homicides in the capital last year reached 135.
Fatals stabbings in the UK at large have also reached the highest level since records begun in 1946 – with 285 in the 12 months ending March 2018.
Jaden Moodie, 14, Nedim Bilgin, 17 and Lejean Richards, 19, are just some of those who have been stabbed to death in London in 2019.
Home Office authorities have been attempting to crack down on knife crime by toughening sentences for people carrying blades and upping police powers.
Detectives are appealing for witnesses to the latest murder. There have been no arrests.
Police were called by paramedics at 2.35pm on Monday to an address in Globe Road, Bethnal Green, following reports of a fight “in progress.”
A Scotland Yard spokesman said: “A man, thought to be aged in his mid-20s or early 30s, was discovered suffering from stab wounds.
“Despite the efforts of paramedics, he was pronounced dead at the scene.
“At this early stage there have been no arrests.
“A crime scene is in place and enquiries into the circumstances are ongoing.
“Officers from the Homicide and Major Crime Command have been informed.”