These dramatic images show the moment thieves sliced a rectangle in a jewellery shop window and snatched £400,000 of valuables in just one minute. Two men can be seen using what is thought to be a chainsaw to cut out a large part of the display window before reaching inside to grab the merchandise - as staff watched from inside the store. The raid saw three men riding motorbikes carry out the heist at Griffin Jewellers in Bridlington, East Yorkshire, on November 10. Scroll down for video . A CCTV still shows two men using what appears to be a chainsaw to cut out a large portion of the window . After removing the glass, they reach inside Griffin Jewellers to grab an estimated £400,000 worth of valuables . It took place shortly before the store was due to close, which meant there was more staff than normal on the shop floor. After the thieves fled with their haul, shards of glass, rings and other jewellery were left scattered on the pavement. Customers at a nearby pub were said to have given chase to the three perpetrators following the incident. Witness Dave Sims, who owns nearby Cosy Times Yankee Candle Shop, said: 'I was driving past Griffins and I could see a man with a chainsaw cutting the window. 'I thought to myself at first that's maybe that's just how they are replacing the glass - then I thought about it some more. Shortly before 5pm on November 10, staff watched as thieves carried out a daring heist in Bridlington . 'When I picked my wife up I drove back around and could see they had just cut out a shape in the window. 'Its just ridiculous that something like this could happen in Bridlington. 'There are not enough police on the street except for community support officers.' Now, the owner of Griffin Jewellers, David White, says the shop has revamped security measures to prevent such an incident happening again. He said: 'I was so impressed with the local support on the day. 'One man even grabbed the rear of a motorbike to prevent the men getting away, but had to let go after he was threatened. 'It really was above and beyond, they even gathered around all the rings on the ground to stop people taking them. Shards of glass, rings and other jewellery was left scattered on the pavements after the thieves fled . The huge square was cut out shortly before the jewellery store was due to close for the day at 5pm on a Monday meaning there were more staff than usual on the shop floor . 'Myself and the staff at Griffin Jewellers would like to express our heartfelt thanks to the people of Bridlington who have offered their support following our recent robbery. 'We have been in-undated with well-wishers. 'In these most difficult of circumstances it has encouraged us all to move forwards from this harrowing event and to carry on offering the same exceptional service for the townsfolk and visitors. 'We are proud to announce, with the busy Christmas period on the horizon that we have managed to restock and add to our already fabulous range of jewellery, watches, gifts and curios.' A spokesperson for Humberside Police said: 'Investigations are still ongoing.' Anyone with information should contact Humberside Police on the non-emergency number 101, quoting crime reference number 2079833. Police sealed off the scene after the raid last month and owner David White says security measures have been increased .
Staff watched as thieves struck just before closing time on November 10 .
Around 100 diamond rings were taken in the raid at Griffin Jewellers .
Daring heist in Bridlington, East Yorkshire, was over in around a minute .
As men fled on bikes, glass and jewellery was left scattered on pavement .
Owner David White says security measures having been increased to prevent such an incident happening again .
These dramatic images show the moment thieves sliced a rectangle in a jewellery shop window and snatched £400,000 of valuables in just one minute. Two men can be seen using what is thought to be a chainsaw to cut out a large part of the display window before reaching inside to grab the merchandise - as staff watched from inside the store. The raid saw three men riding motorbikes carry out the heist at Griffin Jewellers in Bridlington, East Yorkshire, on November 10. Scroll down for video . A CCTV still shows two men using what appears to be a chainsaw to cut out a large portion of the window . After removing the glass, they reach inside Griffin Jewellers to grab an estimated £400,000 worth of valuables . It took place shortly before the store was due to close, which meant there was more staff than normal on the shop floor. After the thieves fled with their haul, shards of glass, rings and other jewellery were left scattered on the pavement. Customers at a nearby pub were said to have given chase to the three perpetrators following the incident. Witness Dave Sims, who owns nearby Cosy Times Yankee Candle Shop, said: 'I was driving past Griffins and I could see a man with a chainsaw cutting the window. 'I thought to myself at first that's maybe that's just how they are replacing the glass - then I thought about it some more. Shortly before 5pm on November 10, staff watched as thieves carried out a daring heist in Bridlington . 'When I picked my wife up I drove back around and could see they had just cut out a shape in the window. 'Its just ridiculous that something like this could happen in Bridlington. 'There are not enough police on the street except for community support officers.' Now, the owner of Griffin Jewellers, David White, says the shop has revamped security measures to prevent such an incident happening again. He said: 'I was so impressed with the local support on the day. 'One man even grabbed the rear of a motorbike to prevent the men getting away, but had to let go after he was threatened. 'It really was above and beyond, they even gathered around all the rings on the ground to stop people taking them. Shards of glass, rings and other jewellery was left scattered on the pavements after the thieves fled . The huge square was cut out shortly before the jewellery store was due to close for the day at 5pm on a Monday meaning there were more staff than usual on the shop floor . 'Myself and the staff at Griffin Jewellers would like to express our heartfelt thanks to the people of Bridlington who have offered their support following our recent robbery. 'We have been in-undated with well-wishers. 'In these most difficult of circumstances it has encouraged us all to move forwards from this harrowing event and to carry on offering the same exceptional service for the townsfolk and visitors. 'We are proud to announce, with the busy Christmas period on the horizon that we have managed to restock and add to our already fabulous range of jewellery, watches, gifts and curios.' A spokesperson for Humberside Police said: 'Investigations are still ongoing.' Anyone with information should contact Humberside Police on the non-emergency number 101, quoting crime reference number 2079833. Police sealed off the scene after the raid last month and owner David White says security measures have been increased .
carry out the heist at Griffin Jewellers in Bridlington, East Yorkshire, on November 10. glass, rings and other jewellery were left scattered on the pavement. Customers at a nearby as thieves carried out a daring heist in has revamped security measures to prevent such an incident happening again. He said: 'I was so of glass, rings and other jewellery was left month and owner David White says security measures have been increased .