A King's College student who was knifed to death in London while returning home from a restaurant with a friend was "entirely blameless", police said.

Mohammed Abdullah Al Araimi, 20, was stabbed near the luxury department store Harrods in Knightsbridge just after midnight on Friday December 6.

The politics and economics student, who was an Omani national living in London, was pronounced dead at the scene shortly before 12.40am, the Met Police said.

A post-mortem examination at Westminster Mortuary gave his cause of death as a stab wound.

He was one of three people fatally stabbed in London in the space of just 24 hours.

His 20-year-old friend was also injured in the attack and taken to hospital for treatment. He has since been discharged, police said.

Detective Chief Inspector Andy Partridge, who is leading the investigation, said: "Mohammed and his friend were returning home from a restaurant when they were approached and assaulted by two male suspects on Basil Street at the junction of Pavilion Road.

"Following the attack, the suspects fled on foot along Basil Street in the direction of Sloane Street.

"I would appeal to anyone who saw two males running along that route, or to drivers who were in Sloane Street around midnight and may have captured any part of this incident on dash-cam footage, to get in contact with my team immediately.

"The victim and his friend were entirely blameless, simply enjoying a meal out together. It does appear that the motive for this cowardly attack was robbery."

Two other men in their 20s were murdered in knife attacks between Thursday afternoon and the early hours of Friday morning in London.

Exauce Ngimbi, 22, was pronounced dead in Hackney, east London, shortly after 2.30pm on Thursday after an altercation with a group, Scotland Yard said.

The third victim is believed to be drill rapper Crosslom Davis, 20, a member of the Harlem Spartans music group, based in Kennington, south London.Mr Davis - who made music under the stage name "Bis" - was pronounced dead just after 3.30am on Friday in Deptford, south-east London.

Anyone with information is asked to contact the Met Police incident room on 020 8358 0300 or call 101. People can also tweet @MetCC.

Alternatively, people can call the independent charity Crimestoppers anonymously on 0800 555 111.