Police have arrested a 14-year-old boy on suspicion of murdering teenager Keon Lincoln, who was killed in a street attack in Birmingham on Thursday.
The suspect was detained on Friday morning, West Midlands Police (WMP) said. He can not be named for legal reasons.
Detective Chief Inspector Alastair Orencas said investigators are still trying to establish exactly what happened during the attack.
He said: "Our investigation has progressed at pace and this arrest is a positive step forward as we try to establish exactly what happened yesterday afternoon.
"Yesterday's events were shocking and tragic. My thoughts are with the boy's family who are being supported by specialist family liaison officers at this incredibly sad and difficult time.
“We're doing all we can to fully understand what took place. Violence like this on our streets is heart-breaking and deeply concerning.”
DCI Orencas added: "I'd urge anyone who saw anything or has any information to contact us as soon as possible."
WMP on Friday afternoon named the victim as Keon Lincoln.
On Thursday, WMP said the boy was "set upon" by a group of youths in the Linwood Road area, about three miles from Birmingham city centre, just after 3.30pm.
The victim was taken to hospital but died as a result of his injuries. It is not exactly clear how he died.
Witnesses at the scene reported hearing gunshots and said the assailants had been armed with knives.
The suspects fled in a white car, which crashed in nearby Wheeler Street, police added.
Officers are speaking to witnesses and checking CCTV in the area. The car has also been seized for forensic examination.
Anyone who witnessed the killing should contact police on 101, or call Crimestoppers anonymously on 0800 555 111.
