DETECTIVES today appealed for witnesses who saw four balaclava-clad robbers flee up a side street to come forward.

The gang made off with tens of thousands of pounds after the raid on a Group 4 Securicor guard collecting cash from Tescos in Hill Street, Blackburn, at 6.05pm on Saturday.

They man-handled, threatened and restrained the guard, before punching him in the face and snatching a cash box.

Det Insp Peter Simm, who is leading the investigation, said officers had been inundated with calls from witnesses mainly shoppers who saw the actual raid. But he said he needed to hear from more people who saw the four robbers flee down the quieter Hill Street.

Such information would be "crucial" as it would probably help police lead police to the getaway vehicle, Det Insp Simm added.

He said: "Anonymous information will be treated in confidence and sensitively if people do not want to give their names."

Call Blackburn police on 01254 51212 or Crimestoppers on 0800 555 111 with information.