A 16-year-old boy and an 18-year-old woman have been arrested over the fatal stabbing of a teenage boy.
Jermaine Goupall, 15, was stabbed to death in south London in Georgia Road, Thornton Heath, Croydon.
He is the 15th teenager to be killed in a knife attack in the capital this year and the second in less than 24 hours. There were 12 fatal stabbings in 2016.
Those arrested were taken to a south London police station where they remain in custody.
A post-mortem examination carried out on Wednesday gave the cause of death as a single stab wound to the leg.
Det Ch Insp Tony Lynes said: "Jermaine was out with his friends when they were confronted by a group of armed men who had made attempts to hide their identities by wearing balaclavas.
"Jermaine tried to run away from the men, but sadly was attacked about 20 yards from the shop suffering a number of stab injuries."