PORTLAND, Maine — The Maine Fire Marshal’s Office has charged three teenage boys with setting fires at a motor home and a lumberyard.

In Vassalboro, a 17-year-old boy is facing an arson charge after the 24-year-old motor home was destroyed Friday on the Hemphills Farm. In Rumford, two 15-year-old boys face arson charges after two fires were set at the Hammond Lumber yard on Sunday. Firefighters were able to put the fires out with little damage.

In addition, two boys in Livermore Falls, ages 14 and 15, were charged with criminal use of explosives after authorities said they built six explosive devices using acid and soda bottles. Some of the devices also contained BBs. They were set off along Green and Baldwin streets. No one was hurt.