A gang of teenagers left a trail of destruction behind as they went on the rampage through quiet city streets.

Neighbours leapt into action, making a citizen's arrest on the ringleader and holding him for ten minutes until police arrived.

The youth then ran for it and one police officer was hurt as he chased him and fell on to a railway line.

Two teenagers were arrested and later released as inquiries continued.

The youths are thought to have spilled on to the streets from a GCSE celebration party in Brighton at around 10pm.

They made their way past homes, vandalising cars and smashing bottles and street lamps.

Rob Young, 42, of Varndean Road, was woken by the sound of smashing glass and swearing at around 10.30pm.

He threw on his tracksuit and a pair of flip-flops and gave chase.

He said: "There was a gang of between five and eight drunken yobs smashing up cars and trying to break street lamps.

"I shouted at them and got an earful of abuse so I went after them."

The gang - thought to have come from Haywards Heath for the party - headed from Varndean Road towards Clermont Road and on to London Road railway station.

Mr Young said: "They were causing complete mayhem, smashing car wing mirrors and kicking in doors.

"I'd kept my eyes on one of them who I'd seen trying to break the lamps. I caught hold of him and made a citizen's arrest. I kept him for ten minutes before police arrived."

But the teenager made a break for freedom as Mr Young handed him over.

Mr Young said: "There were dozens of police on the scene. As I let this lad go he did a runner across the railway line. A copper slipped on to the tracks. He could easily have been electrocuted but he got straight back up and caught this kid.

"It's sickening to think this young officer could have lost his life because of something so stupid."

The officer ended up with a cut face but Sergeant Richard Hamlin, of Brighton police, said the injury was not serious.

He added: "We would like to thank Mr Young for his public-spirited efforts. While youths want to have fun, when they cause damage like this we have to take action."