Firefighters are battling a large fire in Caribou. The blaze is under the jurisdiction the Caribou Fire and Ambulance Department.

Assistant Capt. Danny Raymond said four other departments have responded to help contain the fire as well as the Maine Forest Service, which is using a helicopter to help combat the blaze.

“It’s pretty big,” Raymond said.

“They don’t even have an idea of how many acres,” he added.

Raymond said the fire is in a wooded area near 330 Belanger Road in Caribou. Firefighters responded to initial reports of the fire at about 1:50 p.m. Monday.

As of 5 p.m., the battle to contain and extinguish the blaze was ongoing. Raymond said they do not yet know what caused the fire.

Follow Evan Belanger on Twitter @evanbelanger.