A video of a gang of yobs who allegedly stole a motorbike at knife-point has emerged online.

Police are investigating after the incident at Wilmington Grammar School for Boys in Dartford last Monday.

The owner, who was installing pipes at the site in Common Lane, believes the group who took his £10,000 bike were only teenagers.

He didn’t want to be named but revealed he had only got it the previous week.

He said: “On Monday my bike was stolen at knife-point – while I was working at the grammar school – by a gang of four teenagers I think were aged between 14 to 18.

“They broke through two large gated areas and threatened staff with large blades. Kent Police have been informed but very little has been done.”

He said he’d managed to get his hands on a video circulating on Snapchat which he believes was shot by the gang.

The owner is now appealing for people to help find his MT09 Super bike which has a registration of LR21UMA.

A police spokesman said: “Officers are investigating a report of a motorbike being stolen from inside a school car park in Common Lane, Wilmington.

“The theft is reported to have happened at 12.24pm on Monday. During the incident four people are alleged to have approached a secure school gate before they used an object to break into the grounds where they proceeded to steal a motorbike.

“Inquiries are ongoing to review all the CCTV available.”

A Wilmington Grammar spokesman added: “The police were called to the school on Monday, August 14, following an incident. All staff followed procedures to maintain their own safety.

“As this is now a police matter, we are unable to comment further as we would not want to compromise any investigation.”