TWO armed teenage robbers escaped with around £50,000 after smashing their way into an Accrington building society.

Security guards were delivering cash to the Nationwide, on Broadway, at around 8pm on Monday when the youths struck.

The two Group 4 Securicor guards barricaded themselves into a back room after the robbers, one armed with a knife and the other with a metal bar, smashed through the building society's glass frontage with a street grate.

On fleeing, the guards left three security cases of money behind, which the robbers snatched before escaping towards the Arndale Centre and then turning right at the end of the road.

One of the guards suffered minor injuries as he cut himself on broken glass.

Police are appealing for anyone with information to come forward.

Detective Inspector Joanne Lightbown said: "An investigation is underway and we will be speaking to witnesses and making inquiries to find out who was responsible.

"A substantial amount of cash was stolen and I appeal for anyone with information to contact us as soon as possible.

"The offenders have been described as white youths, aged around 16, both with a slim build and between 5ft 10ins and 6ft tall. Both of their faces were concealed and one was wearing a hooded jumper."

DI Lightbown said: "I would appeal to anyone who saw these young men in the area or recognises their descriptions to come forward.

"I would also like anyone who has information about a missing grate in the area to contact us."

A spokesman for Nationwide said: "We are working with police to ensure that whoever has done this is caught and we will do whatever we can to make sure that the investigation goes as smoothly as possible."

A G4S Cash Services (UK) spokesperson said: "We can confirm that one of our couriers suffered minor injuries.

"We are committed to maintaining the safety of our staff and the general public. We continue to work closely with trade unions, the police, the Government and relevant local authorities to develop initiatives that will curtail the growing number of violent attacks taking place on the cash-in-transit industry."

Anyone with information should contact police on 0845 1253 545, or Crime--stoppers, free and in confidence, on 0800 555 111.