Investigators say they believe a fire earlier this week at a vacant mill building in Sanford, Maine, was intentionally set.

The Maine State Fire Marshal's Office, in collaboration with Sanford police and fire, is investigating a fire on Monday morning at the vacant International Woolen Mill in Sanford.

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The fire was reported shortly before 9 a.m. Monday, prompting a large response from local fire and law enforcement agencies. When they arrived, firefighters encountered heavy smoke and flames coming from a portion of the long-vacant mill complex and worked for several hours to bring the fire under control.

No injuries were reported as a result of the fire.

The building has been unoccupied for several years and is r

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