Fifteen young people, including a girl, have been arrested in connection with the alleged murder of a 16-year-old boy stabbed after a row at a party.

David Nowak was killed after he was followed by a group of youths into a playground near to the birthday party, held in a community centre in Stoke Newington, northeast London. Police have urged local parents to ask their teenagers if they were at the party and, if so, what they saw.

David, who died from a single stab wound, went to the same school as Etem Celebi, 17, who was shot and killed last month as he sat on a wall filling out forms for a job as a lifeguard.

David became the 26th teenager to be murdered in London this year and the 17th to be stabbed to death.

Luke Balgrove, a friend of David, laid three red roses yesterday outside the flat David shared with his mother and sister. He said: “Everyone liked him. He was a nice guy to be around. I knew him when he went to Stoke Newington school. It’s the same school that Etem Celebi went to. It will probably be someone else soon, someone who has got nothing to do with this. People get killed for no reason.” Asked about David’s rumoured involvement in a gang, the DNA Boys, Luke said: “I heard he fell out with them.”

A second teenager, aged 15, was taken to hospital suffering from stab wounds after the attack. His condition was said to be stable. A further two males also attended hospital with stab wounds but neither was serious.

Detective Chief Inspector John Macdonald said that after the stabbing police had stopped a 67 bus and a number of people were arrested. “I believe there were people present who have yet to come forward and would appeal for them as well as anyone who attended the party to contact police.”

As the incident involved teenagers, “some of whom may not feel comfortable in speaking to the police”. Mr Madconald said he was asking parents to ask teenagers if they were present. “I want parents to take some responsibility in identifying who was involved.” Of the fifteen arrested, three were bailed pending further inquiries; the others remained in cusody.

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