Police have made 14 arrests after five separate attacks in London left three men dead and three others injured in the space of 24 hours.
An 18-year-old man was stabbed to death at about 16:42 BST on Friday in Wandsworth, south London.
Police were called minutes later, at 16:54, to Plumstead, south-east London, where a 19-year-old man was shot dead.
A man in his 30s then died after he was stabbed in Tower Hamlets on Saturday afternoon.
In the early hours of Saturday two men were stabbed in Clapham and another was stabbed in Brixton.
The condition of one of the men injured in Clapham is not yet known, while the injuries sustained by the others are non life-threatening.
London mayor Sadiq Khan said he was "sickened" following the death of the two teenagers.
I am sickened to hear that two young lives have been ended within minutes of each other in Wandsworth & Greenwich. Anybody who has information about what happened should do the right thing and call the police, either on 101 or anonymously, through @CrimestoppersUK on 0800 555 111 https://t.co/yqHPMVQvzt— Sadiq Khan (@SadiqKhan) June 14, 2019
US President Donald Trump, who has a long-running political feud with Mr Khan, took to Twitter to say London "needs a new mayor ASAP. Khan is a disaster - will only get worse!"
In response, a spokesman for Mr Khan said the mayor was focused on supporting the city's communities and "over-stretched" emergency services.
The mayor's thoughts were with the victims' families and he "is not going to waste his time responding to this sort of tweet", he added.
Six males - aged between 16 and 19 - have been arrested on suspicion of the murder of the teenager in Wandsworth, who died from stab wounds in Deeside Road.
Tooting MP Rosena Allin-Khan said the killing was "heartbreaking" and "absolutely tragic".
After the shooting in a car park in Hartville Road in Plumstead, three boys aged 16 and 17 and a 17-year-old girl were arrested on suspicion of murder.
Armed police, local officers, the London Ambulance Service and an air ambulance all attended, but the teenage victim died a short while later.
A section 60 order, which allows police to stop and search people, has been authorised in the Greenwich and Bexley areas.
Police were also called to a fight on Bedford Road near Clapham North Tube station in south-west London at 03:22, where two men suffered slash and stab wounds.
Four men have been arrested - two for violent disorder, one for carrying a bladed instrument and the other for possession of a Taser.
At 04:00 police were called by the ambulance service after an altercation at a pub in Coldharbour Lane in Brixton, south London, where two men were injured.
One was stabbed and remains in hospital while the other received minor injuries.
Officers later attended a crime scene in Alton Street, Tower Hamlets, just before 14:00 BST where a man in his 30s, was pronounced dead at the scene after suffering stab wounds.
The deaths take the total number of murders in London in 2019 to 56.
This time last year there had been 77 homicides, 48 of which were stabbings.