A train derailment near Mattawamkeag on Tuesday spilled about 1,200 gallons of diesel fuel.

The derailment occurred at 4:55 p.m. Tuesday at a rail yard in Penobscot County, according to rail operator CSX Transportation. The Lincoln Fire Department, which arrived at the scene, reported that a locomotive collided with a freight car parked on the tracks. Although no one was injured, the collision overturned one freight car and derailed another.

According to CSX, the derailed car struck the locomotive's fuel tank, causing it to rupture and spill about 1,200 gallons of fuel onto the ground. The Maine Department of Environmental Conservation said cleanup crews were able to safely pump another 2,450 gallons from the damaged fuel tank.

The Maine Department of Environment and Rural Development said the agency flew a sheriff's office drone and a Maine Forest Service aircraft to check for fuel spills into the nearby Penobscot River. However, both were unable to detect a fuel haze on the river, suggesting no fuel entered the waterway.

CSX and the Maine DEP said they are working together to clean up the fuel and will continue to monitor the site through the holiday weekend. CSX said the cause of the incident is under investigation.