The Manchester Arndale shopping centre has been evacuated and a man has been arrested.
Shoppers were seen running from the area, The Independent reported, and shops in nearby Market Street were also temporarily evacuated as part of a police operation.
The evacuation comes after the explosion at the Manchester Arena last night, killing 22 and injuring 59, following a music concert.
The Arndale shopping centre has more than 200 stores, including All Saints, Deichmann Shoes and Dorothy Perkins. It is connected by a footbridge to Marks & Spencer and Selfridges.