Police have arrested a man on the M3 and seized a firearm following three alleged armed raid carried out within minutes of each other.

Officers were called to reports that a man armed with a gun had entered the Co-op in Fairmile Road, Christchurch, and stolen some items of food at 5.30pm yesterday. No threats were made and no one was physically injured.

The man is said to have left the store, got into a white Ford Fiesta and driven into the Fairmile service station next door.

It is alleged the man got out of the Fiesta, walked into the petrol station shop with a gun, selected some wine and cigarettes and left without paying. No one was physically injured.

A short time later it is reported that a man entered Fairmile Convenience Store on Fairmile Road and stole some food and cigarettes. It is alleged a man and a woman were assaulted.

As the man got back into the Fiesta and drove away, it is reported the car was in collision with another vehicle.

A 23-year-old man from London was arrested on the northbound carriageway of the M3 in Hampshire on suspicion of robbery, possession of a firearm and driving offences and is currently assisting officers with enquiries. A firearm was seized.

Detective Inspector Andrea Power, of Dorset Police, said: "A full investigation is now underway following the incidents reported to have taken place in Christchurch today.

"I would urge anyone who witnessed any of the incidents and has yet to speak to officers to please contact Dorset Police.

"Officers from the local neighbourhood policing team will be carrying out patrols in the area over the coming days to offer reassurance to the public and deal with any direct concerns."

Anyone with information is asked to contact Dorset Police on 101, quoting incident number 18:330. Alternatively contact Crimestoppers anonymously on 0800 555111 or go to crimestoppers-uk.org.