Two people have been stabbed to death within just 40 minutes in London and a teenager is fighting for his life in hospital after a night of bloodshed.
The first two attacks are believed to be domestic incidents but a third incident hours later left at least two young men injured after a fight being investigated by Scotland Yards gang crime command.
The first death came shortly before 6pm on Sunday in Colindale, north London, where police were called to reports of a stabbing.
A 26-year-old man was taken to hospital by ambulance but died of knife wounds later in the evening.
The victim and the suspect are known to each other, a spokesperson for the Metropolitan Police said. Enquiries are ongoing.
A 34-year-old woman was arrested at the scene on suspicion of murder and remains in custody.
Less than 40 minutes later, police were called to reports of another attack at a home in Brixton, south London.
Paramedics found a woman in her 30s suffering from stab wounds and pronounced her dead at the scene.
A man aged in his 20s has been arrested on suspicion of murder and remains in custody.
It is believed the victim and the man arrested were known to each other, police said. A crime scene remains in place, and enquiries continue to establish the full circumstances.
Then at 9.20pm, an 18-year-old man was stabbed after a fight broke out near Alexandra Palace in Haringey.
Police found the injured teenager in Alexandra Palace Way and he remains in a critical condition in hospital.
A 19-year-old suspect was arrested near the scene of the attack, while a second man suffering stab injuries was later identified in connection with the incident around three miles away in Southgate.
He was taken to hospital with injuries that are not believed to be life-threatening.
The Metropolitan Polices Trident gang crime command is investigating the incident alongside local detectives, and are appealing for anyone with information to come forward.
The stabbings came amid a spate of knife and gun violence in London, which has seen more than 50 murders so far this year.
A nationwide increase in violent crime has sparked calls for increased funding for prevention work andpolice forces, after officer numbers reached a record low.
The governments first ever Serious Violence Strategy said the recording of crime had improved and blamed factors including drug supply and social media for driving tit-for-tat attacks between rival gangs engaged in so-called postcode wars.
But it was heavily criticised after a Home Office document suggesting government cuts had likely contributed to the surge emerged.
Police have increased the use of blanket stop and search powers to seize weapons and some justice powers have been devolved to mayor Sadiq Khan so a bespoke response can be formed in London.
Anyone with information is asked to call police on 101 or contact Crimestoppers anonymously on 0800 555 111.