Police found the victim in a grassy area
An 18-year-old man has been stabbed to death near a bus station in Walthamstow, east London.
A routine police patrol found the teenager lying wounded near Selborne Road at 0140 BST. He was pronounced dead in hospital.
A man in his 20s and a 17-year-old youth have been arrested in connection with the incident and are in custody.
The killing led to the cancellation of Walthamstow's celebration of the handover of the Olympics to London.
The 18-year-old victim is the 24th teenager to be killed in a stabbing or a shooting in London this year.
Clyde Loakes, leader of Waltham Forest Council, said: "I was devastated to learn this morning (Sunday) that instead of celebrating London officially becoming the next Olympic host, in Walthamstow we would be mourning the loss of another young life.
"I intend to call an urgent meeting of the leaders and mayors of the five host boroughs.
"As host boroughs, we must use the power of the Games coming to East London to inspire change in our communities and change for our young people," he added.
'Missed every second'
Officers said they found the youth after they saw two or three males running away from the area.
The two people in custody were arrested near the scene, a grassy area off Selborne Road.
The 17-year-old who was arrested had a minor slash wound to the arm and was treated in hospital.
Met Police Det Ch Insp John Sandlin appealed for information about the incident.
He said: "The incident happened close to a well-lit bus garage in Walthamstow Central."
Flower tributes were left for the victim near the scene
A post-mortem examination will take place on Monday.
Flower tributes were left for the victim close to where he was found.
One tribute read: "We love you so much. You have left a gap in our hearts and you will be missed every second of every day.
"We will miss the sunshine that you brought to our lives. We love you."
According to the British Crime Survey (BCS), overall violent crime has decreased by 41% since a peak in 1995.
Knives are used in about 8% of violent incidents, according to the BCS, a level that has largely remained the same during the past decade.
But the BCS figures do not include under-16s, something which the Home Secretary Jacqui Smith announced this month would change.