GORHAM, Maine (AP) — The Maine Fire Marshal’s Office is investigating the third arson fire to strike the town of Gorham in the past week.

Sunday morning’s fire destroyed an abandoned house on Great Falls Road and caused an injury to a Gorham firefighter, who was knocked to the ground by a fire hose that burst.

Early Saturday morning, a former grange hall on Mighty Road was flattened in a fire that broke out about 1 a.m. The hall recently has been used by a snowmobile club.

The first fire in this series badly damaged an abandoned house on Stiller Road on Tuesday morning.

Four fire marshal investigators have joined Gorham police and fire officials investigating the fires, which have all been ruled arson.

Residents are being asked to report any suspicious activity.