A CCTV picture of a man wanted for questioning about a violent armed robbery has been issued by police.

A samurai sword and a sledgehammer were used by three men in a "terrifying" raid at the Ancient and Modern Jewellers, New Market Street, Blackburn, last month.

The images have now been released in a bid to track the men, who witnesses said were wearing balaclavas during the robbery.

Jewellery and watches were stolen from the shop when it was targeted during opening hours at 4.15pm on Wednesday, December 19.

Police said three men wearing dark clothing entered the shop before threatening staff.

After steal-ing the items, they fled from the shop, where they were joined by two accomp-lices in a Vauxhall estate that made off towards King George's Hall.

Police believe the man in the CCTV images is from the Manchester area and are urging anyone with information to help them to identify him to come forward.

DC Mark Brennan said: "We are keen to trace this man as soon as possible as we believe he may have some vital information to assist with our inquiries. He was last seen acting suspiciously in a Blackburn store just before the robbery occurred and I urge him to come forward so if necessary he can be eliminated from our inquiries."

Speaking at the time one witness said: "I saw these men, about three of them, legging it down the road with a sledgehammer and what I think was a sword.

"They got into what looked like a silver car that had been driving up and down the road outside with its doors open for a while.

"I just thought that the driver was drunk or was a kid messing about originally."

Anyone with information about the man or the robbery is asked to contact the police on 0845 1 25 35 45 or Crimestoppers anonymously on 0800 555 111.