Flying Squad detectives are appealing for witnesses and information following a cash-in-transit robbery in Twickenham on Thursday last week, 5 January.
Police were called at approx. 12:10hrs that day to reports of a robbery of a security van outside the HSBC bank in London Road, Twickenham.
Officers attended but the suspects had fled prior to police arrival.
It is understood that a security guard left his van to return to the bank when a suspect  approached and attempted to pull the cash box being carried from the guard's hand.
When the guard did not release his grip 'suspect 1' assaulted the guard.
'Suspect 1' then fled the scene with a second suspect  on foot along London Road and into Holly Road.
There both suspects got into a black car which then sped off along Holly Road.
The guard was treated by the ambulance service at the scene but was not taken to hospital.
There was no money in the cash box and there were no reports of any firearms used or seen.
The Flying Squad based in Barnes are investigating,
The suspects '1' and '2' are described as:
- mixed race or Asian males
- one with beard
- wearing scarves around their faces
The car used has been described as a big black saloon with the driver being a white male.
As it made off along Holly Road it is believed the car the wrong way down a one section of the road into Queens Road and then onto Kings Road.
DC Mick O'Mahony who is leading the investigation for the Flying Squad said:
"We are appealing to anyone who was in or around the area of London Road at midday on Thursday 5 January.
"Maybe you saw the incident or the moments before the incident?
"Maybe you saw the car make its getaway?
"If you think you did, then please call us.
"Your information could assist the investigation."
Any witnesses or anyone with any information should call the Flying Squad on 020 8247 7931.
Alternatively call Crimestoppers, anonymously, on 0800 555 111.