Video report by ITV London Correspondent Will Davies
The Met Police has added a "significant" number of officers on patrol in south London following a spate of stabbing which left one person dead.
A murder investigation was launched on Saturday after a 22-year-old was killed and nine others were injured in a series of incidents in Croydon.
Two men have been arrested after police were called to reports of five stabbings between 6.56pm and 9.12pm on Friday.
Scotland Yard said the incidents are not thought to be linked.
A 22-year-old man injured at a property in Wisbeach Road, Croydon, was pronounced dead at the scene.
The Metropolitan Police said a group of males attended an address in Wisbeach Road and the victim was stabbed in an altercation.
The Met's Gold Commander for London this weekend, Ade Adelekan, said extra resources would be deployed in Croydon to reassure residents.
"These incidents are not linked, we have uplifted numerous staff into Croydon, we are working with the community, and we are navigating our way as best as we can to make sure that we bring these incidents to a conclusion as best we can," he said.
A resident, who has lived at the block where the stabbing happened for more than 20 years, said the man's mother later showed up "crying and in pieces".
The witness, who declined to be named, told reporters the man was bleeding from a deep cut to his leg and there was "blood everywhere".
She said: "I heard someone shouting but it's normal because people drink outside, I came down and saw two police and two ambulance guys on the ground with him."
She said she saw medical staff make an incision in his torso, adding: "They tried really hard to save him but there was a lot of blood.
"There was blood everywhere, it looked like he was cut in the leg and they tried to stop the bleeding.
"It is terrifying, my son is 19 and I'm worried for him."
Of the nine males wounded across the five incidents, two sustained serious injuries but neither are now in a life-threatening condition.
On Saturday afternoon, police said they had been called to a stabbing near the junction of London Road and Oakfield Road in Croydon shortly after 3pm.
A 24-year-old man has been taken to hospital and police are waiting for an update on his condition.
Regarding the murder probe, Detective Chief Inspector Martin Thorpe, from the Met’s Specialist Crime team, said: “We know that a group of males attended the address and an altercation occurred which resulted in the victim receiving a fatal stab injury.
“I would ask any local residents who saw or heard anything shortly after 8pm on Friday evening to contact police; no matter how insignificant you think your information might be, it could help us piece together what happened.
“I am aware that this was one of a number of violent incidents in and around the south London area on Friday evening but there is nothing to connect these incidents together at this time.”
What happened on Friday night?
Police were called at 6.56 to Chapman Road to reports of a stabbing. Police found a man, whose condition was assessed as not life-threatening, in hospital.
Police were called at 7.15pm after four men, all aged in their 20s, arrived at a south London hospital suffering from stab and slash injuries. One of the men is said to have life-threatening injuries.
Police were called at 8.08pm to Wisbeach Road to reports of two men with stab injuries. One man had already been taken to hospital while the other was pronounced dead at the scene.
Police were called at 8.51pm to a south London hospital, after two men arrived with stab injuries. One of the pair's injuries were said to be life-threatening.
Police were called at 9.12pm to Dingwall Road to reports of a stabbing. Two men were arrested, a 38-year-old on suspicion of GBH, while a man in his 40s was arrested on suspicion of affray and taken to hospital after suffering injuries.
A section 60 order granting police additional stop and search powers was in place across Croydon until 8am on Saturday.
Police asked anyone with information that could help officers investigating these incidents to make contact.
Det Sup Arrowsmith said: “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.”