A robber behind a spate of store raids has held a knife to the throats of two people during two terrifying incidents.

Police believe the same man, wearing a distinctive grey puffer jacket is behind four raids on stores in a day, at stores across east Kent.

Between Thursday and Friday, other raids have taken place at Coral bookmakers in Wincheap and Herne Bay.

The Shalmsford Street Post Office, in Chartham was targeted at 10.30am on Friday.

Scroll down for video. Warning: readers may find some scenes upsetting

Mohammad Rana who has owned the store for 13 years, said: "He came in and there was a customer at the post office counter so he started looking at all the tin food and when he saw the customer had gone he came round to the other counter.

"A female member of staff was talking to my son at the counter and he grabbed hold of her around the neck and put a knife against her neck.

"He was saying give me the money."

Mr Rana had heard the emergency alarm go off and thought it was an accident. He went out into the post office area which is shielded by a glass counter to turn it off when he noticed the man with a knife.

He began to phone the police.

"He saw me calling the police and came over to the post office counter holding the girl. He told me if I made the call he would slit her throat. I knew he couldn't do that so I continued the call.

"He realised the police would come and got scared. He pushed the girl away and ran."

The man left the shop empty handed.

Mr Rana said the girl was very shaken and hasn't yet been able to come back to work.

He added: "I feel scared it might happen again. We want him to be caught and for the police to deal with him.

"He did it to two shops in this area in the same day. He's not scared of anything."

Mr Rana who has shared the shop's CCTV footage with Kent Online said: "The public need to inform the police if they see him. He's been in the same jacket all the time. He needs to be punished for it and made sure he cannot do it to anyone else."

The most recent attack was at Premier Express, in Godfrey Gardens, Chartham, just before 9pm on Friday.

Security worker Roger Hogg, who was guarding a nearby building, had popped into the shop to buy coffees for his team, when the raider walked in. He put a knife to Mr Hogg's neck and grabbed him in a headlock as Mr Hogg fell to the floor.

Mr Hogg said: "He said something like 'open the til or you'll get slit. He had me held in a headlock and the only thing I could do was to focus on the blade so I didn't fall into it.

"My security training had taught me to keep calm and just do everything he said and not fight back."

But watching on CCTV from the family home nearby was Niro Thaya, whose uncle, Thushi Subra, owns the store

He saw his relative and Mr Hogg in distress and grabbed the first thing to hand - a bottle of vodka and confronted the robber. As more commotion was raised the suspect made a dash for it.

Mr Subra said he and his staff had seen the police appeal online about the previous robberies and had said to staff to be careful.

He added: "This man just came in and asked me to give him all the money from the til or he would stab my customer. He had a knife and he had this customer by his neck.

"I was worried, but before I gave him any money my nephew intervened. He is a hero.

The dad-of-two says the incident will affect his life and how he operates the shop.

He said: "We've been here for just under two years and we've never had to worry about this. But now we're going to have to live with the fear for the rest of our lives.

"My six year old son is always in and out of the shop. If he had been in the shop at the time the man could have held the knife up to him.

"For me and my wife, it's going to change how we work."

Mr Hogg, 29, from Maidstone, added: "It was the most petrifying thing I have ever experienced. All that was going through my mind was I didn't want to be stabbed and I wanted to get home and see my girlfriend.

"Mr Thaya saved my life. I'm definitely going round with a card and chocolates to say thank you."

Anyone with information about any of the incidents is asked to call Kent Police on 01843 222289 quoting reference ZY/22732/17.

Alternatively contact Kent Crimestoppers, anonymously, on 0800 555111.