By News Editor, Declan Wilkes

Police investigating the murder of 16-year-old Ben Kinsella arrested more four people last night. All remain in custody.

One was held in Islington, two in Chadwell Heath and one in Bethnal Green.

Two knifes were also found near the scene yesterday. Teams of forensic officers have been combing the area at the junction of York way and North Road near the Caledonian Road tube station. One of the blades, a flick knife, was pulled from a drain.

50 present - few come forward

Detective Superintendent Vic Rae has expressed disappointment at the small number of witnesses who have so far come forward.  He said at least 50 people had been near Ben in and round Shillibeers bar just before he was attacked, but far fewer had been in touch.

Two search warrants have been executed in Islington in connection with the murder investigation.

Police are now acting on the suspicion that Ben was simply in the wrong place at the wrong time. There was however a fight between black and white youths outside the bar and it's believed Ben was singled out after being mistaken as one of the boys from earlier.

Officers are trawling their way through the club's CCTV and examining Ben's mobile phone. He made a final terrifying phone call to a friend in which he said: 'help me, help me' and then the phone went dead. His friend said he was running and sounded petrified.

Four different knifes?

While police have stated there were four attackers, they have made no comment on reports the victim was attacked with four different knifes. A post mortem has confirmed he died of multiple stab wounds.

Two 16-year-olds have also been bailed in connection to the investigation and are due to report back to a police station in late August.