DETECTIVES are hunting an armed gang who threatened two shocked security guards during a violent robbery outside a Poole bank.

The three raiders, brandishing a sledgehammer and crowbar, struck at the Santander Bank, Ashley Road, late on Thursday night.

Police say they are "keeping an open mind" as to whether this attack is related to a similar robbery on another G4S van outside a branch of Barclays Bank in Bournemouth just two days earlier.

Both raids appear to have been carried out by a gang of three robbers, and both raids appear to have targeted cash in transit deliveries.

In the latest incident one security guard suffered a minor graze to his neck, while the robbers escaped in a white Ford Transit van with a black case containing an undisclosed amount of cash.

Detective Sergeant Karen Penn, of Bournemouth CID, said: "I am appealing to anyone who may have witnessed the incident to contact me.

"I am particularly interested in hearing from anyone who may have witnessed a white Ford Transit van driving erratically either before or after the incident.

"All calls will be treated in strict confidence."

The drama unfolded outside the Poole bank around 11.30pm, and the van was later found abandoned less than half a mile away at Alexandra Park.

Officers flooded the area in the aftermath of the raid, launching a search operation which included the force helicopter.

The bank remained sealed off on Friday morning, with a police officer standing guard.

Specially-trained forensics officers have also carried out a detailed examination of the scene.

There was a lot of broken glass at the front of the bank, by the main doors, and this entrance was covered with plastic sheeting.

A security guard helmet also lay on the floor inside the main doors.

Andy Cruickshank director of risk at G4S Cash Solutions confirmed it was another of the company's vans that had been targeted in the Poole raid.

"Fortunately our crew has not suffered any physical injuries but has been badly shaken by the attack," he added. "We are working closely with the police on their enquiries."

A Dorset Police spokesman said: "Detectives are keeping an open mind as part of their investigations as to whether this incident is linked to another similar robbery on a G4S van that occurred outside Barclays Bank in Castlepoint, Bournemouth, at 10.38am on Tuesday, November 3."

One of the Santander Bank raiders was wearing a cap with a white peak and dark hoodie.

The second robber wore a scarf over his head, and the third man wore dark clothing with a white zip.

Witnesses are asked to call Dorset Police on 101.