A 14-year-old boy was subjected to racist abuse before being chased and stabbed to death in Birmingham, police have said, as he was named as Dea-John Reid. Six people, four men in their 30s and two boys aged 13 and 14, have been arrested on suspicion of murder and remain in police custody. Police said the attack on Monday evening took place following an earlier incident involving Dea-John and his friends during which they were subjected to racist language. The Guardian understands the abuse is believed to have included the N-word. The earlier incident escalated, police said, and Dea-John was chased down a busy road in Kingstanding, north Birmingham, before being stabbed. He died at the scene, and a postmortem examination confirmed the cause of his death as a stab wound to his chest. Police are understood to be investigating the links between the first incident and the killing, which happened in the same area of Birmingham. West Midlands police had released a statement on Tuesday denying any racial motive behind the attack, but later said they were keeping an open mind following concern from the local community. Police are examining potential racial motivation for the initial incident, but detectives are understood not be convinced that the killing can be classed as a hate crime. Investigations continue. In a tribute on Wednesday, Dea-John’s family described him as an “incredibly talented young boy”. “We’d like to thank the emergency services for their diligence and support … and the public for their outpouring of love and support throughout this tragic and challenging time,” they said. “This loss not only affects us but everyone Dea-John knew, we have lost a son, his siblings have lost a brother and others have lost a friend. The passing of this incredibly talented young boy will be felt by us all. How many more mothers will have to mourn for their sons for this to stop?” DCI Stu Mobberley from the West Midlands police homicide unit said new information about the case was coming in all the time. “As the investigation has progressed we now believe there was an incident involving Dea-John and his friends shortly before the murder. That quickly escalated, resulting in Dea-John’s tragic death,” he said. “During this precursor incident racist language was directed at Dea-John and his friends; that’s now being investigated. We’re still appealing for witnesses, anyone who saw or heard anything that could help our investigation, to get in touch so we can build up a clear picture of what happened.” The local community activist Desmond Jaddoo, who has been talking to the family since the killing, said he was disappointed the police were dismissive of the possibility of a racial motive early on. He said “people are still uncomfortable talking about race in this country” and that he had raised eyewitness concerns about racist abuse to the chief constable earlier in the week. Police have faced long-standing accusations from communities that they fail to treat hate crimes seriously and deal with them effectively. Police say they have improved hugely over the years. West Midlands police said they were voluntarily referring themselves to the police watchdog, the Independent Office for Police Conduct, over whether they had dealt properly with earlier contact with the victim, believed to have been regarding a fight he had been involved in. The Guardian understands that Dea-John had no criminal record. Detectives are in discussions with lawyers from the Crown Prosecution Service about the evidence they have and whether the suspects in custody should be freed, charged or released while inquiries continue. Anyone with information has been asked to get in touch via a live chat on their website or by contacting Crimestoppers anonymously on 0800 555 111.