A MASKED robber sprayed an unknown liquid into the face of a security guard this morning and fled with an unknown amount of cash.

The guard was walking back to the Loomis security van with a cash box having collected the takings from a petrol station when the 6ft tall raider struck.

It happened at around 8.10am at the Total Garage in Stoddart Street, Shieldfield, Newcastle.

A spokesman for Northumbria Police said: "The offender sprayed the guard in the face with an as yet unknown liquid and demanded he drop the cash box, which he has done.

"The attacker grabbed the box and got into a green Peugeot 306 car, registration number V874 GEF, which was parked on the forecourt and was being driven by another person."

The robber is described as white man and wearing a hooded top.

The car made off along Warwick Street, Heaton, heading towards Armstrong Bridge at Jesmond Dene, where it was abandoned and set on fire.

In the process of the robbery the blue dye on the cash box was activated and it's believed the offenders may have got into a second vehicle.

detectives believe that both this vehicle and the those inside could be contaminated with blue dye.

DS Neil Whitehead, Jesmond and Heaton CID, said: "We're appealing for anyone who saw the robbery take place this morning or who saw the car prior to or after the robbery.

"We're also seeking witnesses to the offenders abandoning the green car at Jesmond Dene and then possibly getting into a second vehicle to make off from the scene.

"There's a strong possibility that the people involved and any car they may have used is contaminated with blue dye. I'd urge people to be vigilant and report anything suspicious to police as soon as possible. Officers are at the scene and we're doing all we can to trace the people responsible."

Anyone with information should call the CID at Clifford Street Police station, Byker via ext 69191, or alternatively Crimestoppers anonymously on 0800 555 111.