Three more teenagers have been arrested on suspicion of murdering a 15-year-old who was attacked by a group of youths.
Keon Lincoln was "set upon" at about 15:30 GMT on Thursday on Linwood Road in Handsworth, Birmingham, and died later in hospital, police said.
A post mortem examination has revealed Keon died from a gunshot and stab wounds.
Detectives have been granted extra time to question a 14-year-old boy arrested on Friday morning.
Another 14-year-old boy arrested later on Friday has been released under investigation.
A boy, also aged 14, was arrested from his home in Birmingham on Saturday night, the force said.
Two other boys aged 15 and 16 were arrested from an address in Walsall in the early hours of Sunday.
Det Ch Insp Alastair Orencas, who is leading the murder inquiry, described the arrests as "significant".
"We are gathering a substantial amount of evidence which will take time to analyse, but we must be thorough to get justice for Keon's family.
"They have been fully updated with the latest developments."