This is the shocking moment a brazen thief threatens brave onlookers who tried to stop him stealing a bicycle in broad daylight on a London street.

The youth was caught on film threatening the passersby with an angle grinder during the raid near London Fields School in Hackney, east London.

Three men were seen grabbing hold of the bike's handle bars after the thieves cut the lock, while others told them to 'f*** off' and dialled 999.
But one thug swung the power tool at them before fleeing with the red Brompton bicycle worth around £1,000.

Dramatic footage of the theft was shared on social media yesterday, attracting more than 15,000 views.

It shows a gang of masked youths targeting a bike chained to railings outside the school as stunned bystanders gather to watch.

Sparks fly as one of the youths uses an angle grinder to saw through the lock, while another jumps and stamps on the bike frame to try and dislodge it.

One man tells the yobs: 'Boys, I'm calling the police. You better go, run. F*** off. What…