A fight involving teenagers – one maybe armed with a knife – broke out in a busy shopping centre on Saturday afternoon.
Eyewitnesses who saw the fight on the upper floor of Nottingham’s Victoria Centre at 15:00 GMT said at least one person had a knife.
Police said there were no reports of injuries and no-one had been arrested.
They said the centre was busy at the time and appealed for more witnesses to come forward.
Insp Paul Hennessy said: “Reports of this nature are concerning and we treat them extremely seriously.
“The public will note a regular presence of officers in and around the city, especially during the festive period, when we see more people enjoying the city’s attractions.”