AN ARMED robber pushed two terrified 16-year-old girls away from a building society counter before brandishing a gun at a terrified cashier.

But the gunman escaped empty-handed from the Halifax Building Society, Borough Road, Darwen, when the female cashier activated a panic alarm, at 2.30pm yesterday.

The two girls, who are believed to have recently finished their GCSE exams, and the 58-year-old cashier were said to be "utterly traumatised" by the hold-up.

The gunman, aged between 25 and 35, ran off after repeating his demands for cash two or three times.

There were no other customers in the building society at the time, although a man entered as the gunman fled.

Today, a businessman described how the two girls ran into his business full of tears and asked him to phone the police.

The businessman, who did not want to be identified, said: "A man walked into the Halifax, held up a black gun and said 'Money now'. I called 999 immediately. I did not see the man. I understand he fled the scene."

The businessman gave the girls glasses of water until their parents came and the police took statements.

Detectives were today appealing for anyone who may have seen the offender before or after the attack to come forward.

He is described as white, 6ft tall and broad, with short hair. He was wearing a two-tone baseball cap with a dark peak and designer label on the forehead part.

He also wore a blue, hooded tracksuit top with three yellow stripes down the sleeve and a motif on the left breast, a light-coloured T-shirt underneath and jeans.

It is believed the man ran off towards Darwen Leisure Centre.

Detective Inspector Neil Hunter, who is heading the investigation, said no physical injury was caused in the raid but that the psychological effects were huge.

He said: "The two young 16-year-old girls are badly shocked.

"The female cashier, having had a hand gun thrust in front of her and threatened with demands for money, is badly shaken.

"There are no physical injuries but with attacks of this nature the effects are emotional and psychological.

"We are keen to speak to anybody who was in and around the Halifax Building Society yesterday at 2.30pm and who saw anybody fitting the description immediately beforehand."

Witnesses should contact Darwen CID on 01254 353841 or 353842.