The new Lincolnshire Co-op shop on Sincil Street has been closed after police and ambulance crews were called to an incident.
Shoppers were told to vacate the store just after 2pm on Monday, September 30.
Lincolnshire Police and East Midlands Ambulance Service crews attended and people watched what appeared to be a struggle with a man inside.
One man was injured and was taken to hospital by paramedics. Police said they believed his injuries were self-inflicted.
The shop was closed to customers and staff inside were seen cleaning broken glass from the floor.
Two shoppers told a Lincolnite reporter at the scene that a man had made threats with a bottle, but this has not yet been confirmed by police. One shopper said: “I heard a lot of racket and saw feet flying around, presume he was being pinned down.
“Next thing I know there was wine bottles flying around then when they brought him out. I saw he had blood on his neck and knuckles.”
A Lincolnshire Police spokesperson said: “We received a report of an injured man in Sincil Street, Lincoln at 2.10pm. It is believed the injury was self-inflicted.
“We attended along with EMAS. The man has been taken to hospital.”
It is being dealt with under incident 224 of today.
This is a developing story and will be updated as soon as more information is available.