Police deployed firearms officers and dog teams to reports of a gun seen in Cardinal Park yesterday evening.

Security staff working there contacted Suffolk Constabulary around 5.20pm saying they had seen a group of between 15 and 20 young people, one of whom appeared to be holding a gun.

One youth had been detained, a force spokesman said, with a search is continuing for the rest of the group in the nearby area.

They added a bag had been recovered with a BB gun inside.

The spokesman added no shots had been fired and no one has been injured.

One eyewitness said she saw armed officers approach “a crowd of teenagers” as she and her eight-year-old son left the cinema.

“I was about to cross the one-way to go to the car park across the road when I heard sirens on the main road,” she said.

She described seeing the police car “screech to a halt” and two officers, both with guns, move towards the group of youths before arresting one.

“I didn’t know what they were there for so I wanted to get my son away in case anything happened,” she added.

“It’s not exactly what I was expecting on the way back to the car.”