One man has died and nine others have been injured in stabbings around Croydon, south London, on Friday night, police have said.
Metropolitan Police were called to five separate incidents but they are still investigating whether any of them are linked.
They have enacted additional stop and search powers across Croydon overnight.
Two of the injured victims are in critical condition. Two men have so far been arrested.
The incidents were:
Just before 7pm police were called to Chapman Road. A man is in hospital with injuries not thought to be life-threatening
At 7.15pm, four men aged in their 20s took themselves to a south London hospital with stab and slash injuries and one of them is in a life-threatening condition
At 8.08pm, police were called to reports of two men with stab injuries. One of them was taken to hospital before police arrived but his condition is not life-threatening. The other man was found at the scene but he died
At 8.51pm, two men went to hospital with stab injuries and one is in a life-threatening condition
At 9.12pm police were called to a stabbing on Dingwall Road where they arrested a man on suspicion of grievous bodily harm. The victim, whose injuries are not thought to be life-threatening, was also arrested.
Detective Superintendent Nicky Arrowsmith said: “Sadly, tonight we have seen a number of needless and completely abhorrent violent altercations, including one that has tragically resulted in a loss of life.
“Officers will be on patrol throughout the night across the South Area Command Unit, with additional resources from the Violent Crime Taskforce and Territorial Support Group deployed to deter and prevent any further violence.
“A Section 60 Order granting police additional stop and search powers is in place across Croydon, until 8am on Saturday, 6 February.”
She urged anyone with information to contact police, adding: “Our officers continue to work around the clock to identify and pursue offenders, bring perpetrators to justice, support victims, take weapons off the street, engage and reassure the public, and keep our communities safe in London.
“But we are not complacent and cannot do this alone.
“We work closely with our communities as they are key to understanding and knowing what is occurring locally.
“We need to hear from anyone who has information about crime, those who carry a weapon, or those who exploit others for gain or revenge, while putting young people’s lives at risk – we need this information to help keep London safe.”