ARMED police descended on Poole yesterday after a knife-wielding robber threatened customers at a builders merchants.

One builder was reportedly threatened with a large serrated plaster’s knife, which the robber held to his throat before demanding his van keys.

A suspect was eventually arrested by Dorset Police half-a-mile away in the Kenyon Road area, Oakdale, after being challenged by a resident who believed he was attempting to break into a neighbour’s garden shed.

“I was in my bedroom and saw him in a neighbour’s garden,” said 21-year-old Hicham Brown.

"I thought, ‘hang on, this guy looks a bit dodgy.’ Then he went up to my next door neighbour's shed and started shaking the door about.

“At this point I darted downstairs and out the back - he was running around a van at the corner. He had a knife in his hand.

“He came up to me with the knife. I said ‘that isn’t your gaff’ and he just started mumbling about how he wanted to buy a caravan. Then I just said again ‘that isn’t your gaff'.

“He looked up and saw the police helicopter and went off down the road.”

Seconds later police arrived on scene and arrested the man.

Hicham said “As the guy looked up at the police helicopter, I saw the police armed 4x4 coming towards him. They jumped out of the car and just jumped on him. The police had guns. He’d tossed the weapon away but the next thing I knew he was on the ground. He went down like a sack of potatoes."

Neighbour Betty Graham, of Kenyon Close, told the Daily Echo: “As I came out, about 8.45am, I saw all the flashing lights. Initially I thought there had been an accident. There must have been about 10 police cars.”

The drama unfolded at Buildbase, Ringwood Road, Poole.

Assistant manager Jamie Piroozfar, who was one of three men who rushed to tackle the raider, explained: “A customer was in the front car park, he’d got his materials and was parked up. This lad jumped over the fence, opened his door and asked him for a cigarette.

“The customer told him he didn’t smoke – with that this lad pulled out this plasterer’s knife, put it to the customer’s throat and demanded the keys to his vehicle.”

Jamie said the customer pushed him away, before the man ran out onto Rosemary Road. Then the shocked customer, his business partner and Jamie charged out looking for him.

When Jamie came back to call the police, the other two men challenged the knifeman before backing off. “This guy was saying I thought it was my father’s van which was stolen two days ago,” Jamie said.

“They didn’t detain him, I think they were worried about what he was going to do. I guess it’s better to walk away.”

Dorset Police confirmed officers were called after 8.30am and were told a man wielding a knife had tried to break into a shed in the Ringwood Road area.

A search, involving the police helicopter and dogs, was conducted in a wide area including Ringwood Road, Rosemary Road and Kenyon Road .

The police spokesman confirmed a 25-year-old Poole man had been arrested on suspicion of attempted robbery and was helping police with their inquiries.