AN armed robber walked into a petrol station and threatened staff with a gun, police said.

The thief walked into the Shell garage, also known as Stop N Steer, in King Street, Blackburn at around 8.30pm last night with a gun and demanded money from the counter staff.

Officers said a male member of staff was threatened by the robber with a gun, before he fled the shop.

Police were called to the scene and the police helicopter used to search the area.

Detective Sergeant Melissa Kelly confirmed the incident happened at the Shell garage in King Street. 

A police spokesman said: "We were called at 8.30pm to an incident at a garage in King Street, Blackburn.

"A man with a gun had gone in and demanded money from counter staff.

"He threatened one male staff member behind the till with a gun before fleeing the store."

A 23-year-old man, of no fixed abode, was arrested a short time later on suspicion of robbery.

A newsagent on the road who heard about the incident from a customer said he had been left 'shocked'.

The newsagent said: "I was told by a customer in the shop this morning that they had seen police with a dog chasing a man out of the Shell garage where they had been an armed robbery.

"The police then managed to catch the man nearby.

"I am shocked by the incident and hope everyone in the shop is okay."

Another shop keeper on the road said: "I just heard from a customer that there had been an armed robbery at the Shell garage.

"The customer said they went to get a takeaway and were stopped by a police officer, as the road had been closed off.

"They said there was a lot of police about."

Wensley fold councillor Quesir Mahmood said: "It's quite shocking that an incident like this has happened, as it's not something we've experienced much in the area.

"I'm glad that someone was arrested shortly later and I hope that the law will take its course."

Detectives are now appealing for anyone who witnessed the information to call 101, quoting log number 1345 of August 23.