It wasn't until smartphone footage of the gun-toting man did the rounds the following day that the horrified parents realised their children had been telling the truth.
One mum told the paper that her eight-year-old daughter had run in claiming that a man with a gun had given it to a little boy to hold.
"I'm ashamed to say I didn't really pay any attention to her but when I saw the photograph the next morning I couldn't believe my eyes," the shocked woman said. "I called the police and there were cars and vans everywhere and lots of armed officers."
Her little girl was then asked by the police to draw the gun, but was unable to do so, instead, according to her mum, crayoning 'big shiny gold bullets in a magazine'.
Another parent told reporters that her son had seen a man with 'a big gun with bullets in it' - she too admitted she thought he had been making it all up until she saw the photograph.
Armed police officers attended the area in Northfields, Leicester and surrounded the playground. They later arrested a man of 57 in nearby Brighton Road. He was later released on bail pending further inquiries.
A number of imitation firearms were reportedly discovered at the time of his arrest.