As film pitches go, the idea of students playing zombies being hunted by armed police has all the makings of a blockbusting zom-com.

But in reality, the teenagers were in real trouble – from officers investigating claims that a gunman was on the loose.

Passers-by had called 999 after spotting a man ‘running around with a gun’ – which turned out to be a cheap toy pistol – as armed police raced to cordon off the town centre in Woking, Surrey.

Officers chased down the terrified students, who had not told the police or council they would be making a film that involved one of them dashing in and out of a derelict building, shooting dead a cast full of zombiefied actors, with not one passer-by harmed.

Eyewitness Greg Abbott, 31, said: ‘It would have been funny had it not caused so much disruption to the town centre.

‘These kids were running around filming a movie and one of them had a toy gun and kept popping in and out of this empty building, taking shots at zombies.’

A spokeswoman for Surrey police said: ‘The teenagers had been given permission by the owner of a derelict building to film there, but as one of them kept coming in and out armed with a fake gun, we received a lot of calls from witnesses.’