There was a heavy police presence including armed officers in the centre of Dursley yesterday morning, Thursday.
Numerous police cars were spotted at the back of Iceland, near to the library.
It has now been confirmed that police were called as there was concern for the welfare of a person at an address near the town centre.
A spokesperson for Gloucestershire police said: “Upon police attendance the person said they were in possession of a firearm and armed officers were deployed to the address due to this.
“The person spoke with officers and they were detained under the mental health act. They are now receiving support.
“An air weapon was found following a search of the property.”