A GROUP of teenagers dressed as ninjas sparked a security alert in the centre of Cambridge.
Police were called in after an officer noticed the group dressed from head to toe in distinctive black Japanese warrior outfits.
The teenagers, who describe themselves as street acrobats, were warned about their behaviour by officers and ordered to remove the offending clothing.
Student Jon Whymark, who witnessed the drama unfold on Wednesday afternoon, said: "It was ridiculous to believe these kids were anything more than street performers.
"I was just dumfounded by the police response and the reaction of some American tourists who seemed to think Al-Qaeda were about to attack."