"This was an incredibly nasty incident and the staff were very shaken but fortunately unharmed, which is our number one priority.
"We will be offering them any assistance and any support they require after this terrible incident.
"We are also working with the police and hopefully witnesses will come forward to help catch these people."
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We're one week into December and the countdown to Christmas is well underway. Read the latest in ITV News Anglia's Christmas Shout Outs.
The grandparents of missing serviceman Corrie McKeague have travelled 425 miles from their home in Scotland to retrace his last steps.