The Metropolitan police say a third individual went to the hospital with what they suspect were gunshot wounds.
A gunshot in a south-east London residential neighbourhood claimed one man's life and injured two others, while a separate knife assault a few miles away claimed another man's life.
Following what was called a "senseless act of violence" in the vicinity of Wells Park Road, Sydenham, police urged witnesses to come forward.
When emergency personnel arrived on Sunday just after 10.10 a.m., they discovered a guy who had been shot and died at the site. A woman was transported to a hospital with non-life-threatening gunshot wounds to her legs.
The Metropolitan police say a third individual went to the hospital with what they suspect were gunshot wounds.
Cmdr Peter Stevens of the Met said: “I know people will be shocked by this senseless act of violence, all the more so on a Sunday morning in a residential area. Officers will also be patrolling the area. I urge anyone with information to speak with those officers.”
No arrests had been made by Sunday afternoon and police were trying to establish the victim’s identity and contact his family.
Another man died in an apparently unconnected incident in south-east London on Sunday morning at a busy weekend market.
A man in his 60s was arrested at the scene after police were called at about 10.40am to reports of a number of people being stabbed in East Street, Walworth. Three were found with injuries, one of whom died at the scene. A man and a woman were taken to hospital.
Images from the scene showed police and emergency workers tending to someone on the ground between stalls at the market, which opens between 8am and 4pm at the weekends.
A father said he worried for the safety of his children after witnessing the aftermath of the stabbings. Siraj, 46, who lives locally and did not wish to give his surname, was walking through the market when he saw police cars and ambulances going past.
He followed them and found two injured people lying on the ground.
“It was terrifying,” he told the PA news agency, adding he felt lucky the victims were not him or his children. He said the area had “always been safe” but now he was worried. “I feel unsafe to send my kids to school now,” he added.
Stevens said: “Tragically, a man lost his life this morning, and officers are working hard to establish exactly what happened and to provide support to his family.”
The incident is not being treated as terrorism and no one else is being sought by police at present. The mayor of London, Sadiq Khan, said on X on Sunday: “Violent crime devastates our communities and must be tackled in all its forms. As mayor, I’m supporting our police to bear down on violence, while addressing its root causes through prevention.”
Anyone with information has been asked to call police on 101 or message via X on MetCC, or contact Crimestoppers anonymously.