Armed officers were deployed to a property in Friskney when police received concerns a man was in possession of a firearm.
A statement from Lincolnshire Police reads: “We received a call at 3.47pm on September 16 reporting a concern for safety.
“This related to a person at a property on Dickon Hill Road, Friskney.
“A man was believed to be in possession of a firearm. Negotiators and armed officers were deployed.
“The male was detained under the Mental Health Act.”