HARVARD, Mass. - A four-alarm fire spread quickly on Monday at the Fort Devens South Post Range Complex.

According to the Devens Fire Department, the fire reached roughly 300 acres by Monday night. The fire was started by munitions being used during a drill. 

According to MassDevelopment, windy conditions moved the fire quickly through the munitions range. Firefighters had to fight the fire from the roadways to avoid the live munitions. 

Due to the danger of an active fire on the range, all non-firefighting personnel were pulled from the range by 7:30 p.m. and the fire was allowed to burn through the night.

Fire crews are back on scene on Tuesday at Fort Devens South Post.  Regional fire departments from Harvard, Lancaster, Ayer, Shirley and Bolton were some of the departments providing mutual aid.