A student filmmaker has described the terrifying moment police marksmen aimed guns at his head while he shot a gangster-inspired project on the streets of Highbury.

Ryan O'Donnell, 16, and four other London Screen Academy (LSA) students were filming a scene inspired by the Hitman franchise with a BB gun in Highbury Terrace when cops were called on Monday.

Ryan and his four classmates were ordered to get on the floor and had actual guns pointed at their heads, before they realised there was no genuine threat.

Speaking to the Gazette, Ryan said he missed the lesson where teachers explained not to use imitation firearms in public. He has since been suspended for a week and has apologised for wasting police time.

He told the Gazette: "We noticed the car pulling up, it was really close to hitting us, we had to get out the way.

"All of a sudden they jumped out. I was like: 'Please don't shoot. I just didn't want to get shot. It was panicky getting a gun pointed in your face and being told to get down by everyone. I was a little bit shook and I didn't want to do anything that could get me shot."

Officers cuffed the teenagers and lay them face down in the road, a short walk away from their academy in Highbury Grove.

"We were all worried but the ones with me actually treated me quite nice once they saw me complying. My other friend told me he was treated a bit rough. His handcuffs were tightened and he had marks on his wrists. He didn't go into college today because he was shook up."

Ryan says his parents were more worried than angry as they saw pictures circulating online of officers holding a gun to his head.

The Met Police's guidelines for filming stipulate that people using replica, imitation or airsoft firearms must consult the force in advance for permission, and get a film weapon crime reference number.

The guidelines also stipulate film crews: "Tell us about any activity involving weapons to prevent the emergency deployment of armed police."

Ryan added: "I'm obviously in trouble but thankfully I'm not permanently excluded. Obviously I'm sorry for the whole thing and whatever's happened."

He said the prop was a BB gun but he'd left all its pellets at home and hadn't made any noise with it, and thinks this is one of the reasons he wasn't arrested.

A police spokesperson said: "Firearms officers attended the scene and a group of school children were stopped and spoken to.

"A BB gun was recovered and school staff have been informed; they will be dealing with the matter. No arrests made."

LSA, which opened in September, has been approached for comment.