New London — A two-alarm fire damaged a multi-family home at 212 Montauk Avenue early Thursday morning, displacing at least five residents.

Firefighters responded at 12:27 a.m. for a report of smoke in a second-floor apartment of the three-story building that contains two vacant storefronts on the first floor and four apartments above.

Firefighters knocked down the bulk of the fire in about 20 minutes but Battalion Chief Jeffrey Rheaume said firefighters were at the scene for more than an hour, chasing hidden pockets of fire in void spaces and in the attic.

One firefighter was treated at the scene for fire debris in his eye but there were no injuries among the residents. Rheaume said the Red Cross is aiding displaced residents. The fire is under investigation by the New London Fire Marshal’s Office.

New London firefighters were aided by the Waterford Fire Department, Submarine Base Fire Department, Poquonnock Bridge Fire Department, Groton Ambulance, Lawrence + Memorial Paramedics, New London Police, Salvation Army Canteen Unit, Eversource Gas & Electric and New London Public Works Department.