The victim of a fatal stabbing at an east London shopping centre has been named as 21-year-old Beniamin Pieknyi.
Police believe Mr Pieknyi and a friend were involved in an argument with a "large group of young males" before he was stabbed at the Stratford Centre on The Broadway.
He was pronounced dead at the scene at 22:30 GMT on Tuesday, despite efforts of people nearby to save him.
A post-mortem examination concluded that he died of a stab wound.
Det Ch Insp Will Reynolds, of the Metropolitan Police, is appealing for the men involved to come forward.
"It could be that you witnessed the incident and we need to eliminate you from the investigation as soon as possible," he said.
"The shopping centre was busy at the time of the incident and a number of witnesses have already come forward to help police with investigations. We are grateful for this assistance and for those who provided emergency first aid to the victim."