There is understood to be a 100m cordon in place around Grand Arcade in Cambridge following reports of a suspicious package.
Bomb disposal teams have been dispatched, police are expected to be in the area for several hours.
More top news
Dappy admitted brandishing a butcher's knife during a row with his partner Imani Campbell outside their home in Hatfield.
Most places dry overnight. Showery rain tomorrow
Ipswich Town are set to confirm the signings of Cardiff City midfielder Emyr Huws and Manchester City winger Bersant Celina.