"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."
More top news
For some parts of the region, there's a risk of thunderstorms tonight before a mainly fine weekend.
Suffolk fire crews and care home managers have been practicing a major fire at a nursing home near Bury St Edmunds.
Last minute preparations are going on at the church where Princess Charlotte is to be christened on Sunday