Shakilus was repeatedly stabbed in south London
Five people have been arrested in connection with the murder of 16-year-old Shakilus Townsend.
Two male teenagers, two men, and one girl were being questioned at two police stations in south London.
Shakilus, from Deptford, south-east London, was beaten with a baseball bat and repeatedly stabbed in Thornton Heath on Thursday afternoon.
Residents tried to stem the flow of blood with towels but the teenager died in hospital shortly after midnight.
Officers made one of the arrests around 2100 BST on Saturday and the other four on Sunday morning.
The two male teenagers arrested are aged 16 and 17, the men are aged 18 and 22, and the girl is 16 years old.
Home Office minister Tony McNulty said on Sunday he would like a debate about whether hospitals should be asked to release figures on people treated for stab wounds in an effort to improve knife crime statistics.
He said he recognised there would be issues over patient privacy but said a balance needed to be struck between this and the need to know the full extent of knife injuries.
After Shakilus was stabbed local residents dragged him into the communal doorway of their building before trying desperately to save him.
An air ambulance was scrambled and the teenager was eventually taken to hospital by road after being treated at the scene.
One line of inquiry detectives are following is that the attack was sparked by a row over a girl.
Floral tributes and cards have been left at the scene where the teenager died, where relatives including his parents Nicola and Derek gathered yesterday.
Residents living near the scene who tried to save him mingled with his friends and relatives.
Tributes to Shakilus have also appeared on the online memorial site Gone Too Soon.
On Saturday, Shakilus's stepmother, who wished not to be named, said: "There's no punishment and that's why the children do what they do.
"We as parents are very angry because nothing is being done and every single day we're burying a child.
"When these youths commit these crimes they must be sent to Iraq."
Shakilus is the 18th teenager to be shot or stabbed to death in London this year.