FARMINGTON — Police on Saturday night arrested a man after they blocked off part of Unionville to investigate the report of an armed man possibly holding a hostage in a nearby house.

Nobody was injured, and no details about the arrest were available at 10 p.m.

Sometime after 8 p.m., police put out a call describing an armed man in a T-shirt who was possibly near the Farmington River in the area of Mill Street.

Police shut down Mill Street to traffic, and directed patrons of the nearby Matthew's restaurant to stay inside while they investigated. Diners who were eating on the outside deck were ordered inside.

Police turned back traffic at Walgreens sometime around 8:30 p.m., and by 9:15 numerous officers and patrol cars were gathered at a nearby retail parking lot, said Mike Cioffari, an employee of the Bottle Shop. Police focused attention on a Mill Street house, and a dispatcher described the scene as a possible hostage situation. At least one ambulance was called to stand by.

Police got into the house to search around 9:40 p.m., and soon afterward they advised that the scene was under control and that Matthew's patrons were free to come and go.

Police supervisors were working at the scene and could provide no details about the suspect, whether he had a gun or whether he'd taken a hostage.