It's a scene Lewiston fire fighters are all too familiar with in that city. A total of four fires have kept them busy through the overnight hours into this morning, and investigators say all were arson.

One fire was reported on Nichols Street and two more later in the morning on Howe Street, and another on Oxford street. A neighbor on Howe Street reported hearing an explosion.

The Red Cross is on the scene to assist displaced residents and a shelter has been set up.

Sgt. Ken grimes with the state Fire Marshal's office said at a press conference this afternoon that it's confirmed all four fires were intentionally set, as was a fifth attempted arson in which no significant damage was done to the building. Fire investigators are working with Lewiston police to try and determine who's responsible for the fires.

Last year the City of Lewiston lost 10 buildings in arson fires during the months of April and May.