A 31-year-old man has been stabbed to death by two attackers on a moped during an early-morning altercation in south-east London, police said.
The victim was fatally wounded during a clash in which shots were also fired in King William Walk, Greenwich, the Metropolitan Police said.
He had first been approached by the pair at 12.15am on Saturday.
The assailants, both male, then fled the scene on the moped and emergency services arrived to find the man with stab injuries.
Despite the efforts of the police and the London Ambulance Service, he was declared dead at the scene.
The victim's next of kin have been informed, police said.
Detectives have launched a murder investigation and said they "retain an open mind as to the motive".
With the killers still at large, anyone with information was urged to call police via 101 or call Crimestoppers on 0800 555 111.
The killing is the latest harrowing crime to hit the capital in which the perpetrators were riding a moped.
On Thursday night, a string of acid attacks were allegedly carried out by two men driving a scooter.
Their mode of transport allowed them to inflict five attacks on fellow moped drivers in a 90-minute window across north and east London.
Two teenagers, aged 15 and 16, were arrested on suspicion of grievous bodily harm and robbery.
They remain in police custody.