Two men armed with an axe tried to smash their way into a Crayford jewellers before getting away on a moped.
Police are investigating the incident at Cash for Gold in Crayford Road which happened just before 5pm on Wednesday.
The suspects were unsuccessful in their attempt to rob the shop because of the reinforced windows.
Victor Oyetunji, 60, of Hall Place Crescent, Bexley saw the dramatic incident unfold and says he felt enraged when he saw the two hoodlums trying to smash their way into the shop.
He told News Shopper: "I saw these two guys ride up on scooters with crash helmets on so you couldn’t see their faces.
"They used sledge hammers to try and break into the glass of the shop. The grandfather-of-two was appalled to see the crime happening in Bexley.
He said: "I’ve lived here for 11 years and I’ve never heard anything like it.
"It’s the kind of thing which would happen in Central London.
"I felt so angry when I saw it happened - I would have liked to tackle them.
"They were only around for about two minutes.
"It’s not right to go around doing something like that.
"I just wish I could have done something."
A police spokesman said: "Police are appealing for information and witnesses following a robbery at a jewellers in Dartford.
"Two suspects pulled up at the shop on a motorcycle.
"The pillion passenger - armed with an axe - smashed the window and reached in grabbing items of jewellery on display, before the suspects made off on the motorcycle, turning into Crayford Way.
"The driver of the motorcycle is described as a white man, aged 18-20, wearing a white full faced crash helmet and white T-shirt.
"The pillion passenger is described as a white man, aged 18-20, about 5ft 10ins tall, wearing a black full faced helmet, black tracksuit and black gloves. He also had a grey/white rucksack on his back.
"Officers from the Flying Squad are investigating."
Detective Constable Andy Burrowes of the MPS Flying Squad said: "I would appeal to anyone with knowledge that would assist police in identifying these robbers to come forward and speak with us."
Anyone with information that may assist police should call Detective Constable Andy Burrowes of the Flying Squad on 020 8345 4238. You can also call Crimestoppers anonymously on 0800 555 111