An unmarked police car ploughed into a market stall in Surrey Street this morning after an armed robbery sparked a road chase.

The vehicle collided with a vegetarian food stall after a robbery at the Post Office in High Street just after 9am.

Police have arrested five people following the raid, which left two people needing hospital treatment.

Robbers were reported to have leapt over the counter in the post office and demanded cash before being tackled by officers as they fled.

The unmarked car rolled into the market stall as officers made their fifth arrest, of a man in a parked car in Scarbrook Road, at about 11.30am.

A market stallholder, 53-year-old Russell Smith, suffered a gash in his knee when the police car rolled into him.

The post office in High Street is shut following the robbery

Pic: Maxine Formosa

The Metropolitan Police confirmed officers from its Flying Squad robbery team and its specialist firearms command had arrested five men and recovered a firearm and cash following the post office raid.

Among those detained were a 22-year-old from Lambeth who was in a car near the post office. Three other men were stopped as they tried to flee on foot.

A large number of police officers, including from the force's Flying Squad robbery team, flooded into Croydon town centre.

A 13-year-old boy from Wallington, who was shopping with his mum Sonia Edwards at the time, witnessed two armed robbers fleeing the post office and being tackled by police.

He said: "They jumped over the counter, shouting and swearing, filling up the bags and asking for money. One ran off through Primark and the other ran around the corner but they caught him.

"There was an unmarked car outside, like undercover police, parked outside the post office."

He added: "It was very shocking. I thought it was just a fight, but when I saw the gun I was shocked."

Ms Edwards, 49, said: "It was an old rusty gun, like it had been used over and over again. They had it in his pocket for ages while they held him to the floor. They couldn't actually take it from his pocket because of how he was laid, so they held him for ages."

Mr Smith, 53, of York Road, Selsdon, said he did not blame police for his injury.

The trader, who sells flowers in Surrey Street market, said: "I turned round; there was a car there and it hit my knees. The police car hit me. It rolled from up on top and onto me.

"I think I'll just have a bit of swelling, a bit of bruising. I'm all right - I'm not shaken up. They were very apologetic - and they were only doing their job to get four nasty guys."

The car then rolled into the neighbouring vegetarian stall, badly damaging it.

Greg Kirby, 22, one of the owners of the stand, said: "Some guys ran past with police hats and guns. I saw in the window of the tent that there was a car rolling towards us.

"It hit the market stall opposite us - well, the man who works there - and then it came straight through our tent. We managed to get out the back but it caused quite a lot of damage.

"We came out the tent, and there were more armed police running down the road. It was chaos really - a lot going on. We've had two or three hours of ambulances, police cars."

London Ambulance Service said it was called to High Street at 9.09am.

A police spokeswoman said witnesses' claims that shots were fired during or following the robbery were false.

All five men arrested remain in police custody this afternoon.

Did you see what happened? Call the newsdesk on 0208 722 6351 or email chris.baynes@london.newsquest.co.uk