Detectives are linking the murders of two Tamil men which happened within a few hours of each other in north London.
The two men were killed within hours of each other
Partheepan Balasinghan, 23, from Sri Lanka, died after he was attacked by a gang of men carrying various weapons outside a restaurant in Wembley, north-west London, at 0100 BST on 8 July.
One hour later, 18-year-old Cisho Kumar Balachandiran was found sitting in a river in Wanstead, east London, with serious injuries to the head and body. He died later in hospital.
Earlier that evening he had been involved in a fight between two gangs at the Icon Bar in Ilford, Essex.
Scotland Yard has confirmed that both murders are now being investigated by the Specialist Crime Directorate West.
In both cases the suspects are thought to be Sri Lankan.
A police spokesman said: "We have had some positive responses from the Tamil community and would like to thank them for their help so far.
"However, we are anxious to speak to anyone with information about the murders."