MATTAWAMKEAG, Maine (AP) — A train carrying crude oil derailed Thursday in eastern Maine, resulting in a minor spill that didn't cause any immediate environmental damage, officials said.

Fifteen cars of a 96-car train went off the tracks at about 5 a.m. in Mattawamkeag, a town of fewer than 700 people 60 miles north of Bangor, said Cynthia Scarano, executive vice president of Pan Am Railways.

Thirteen of the cars fell onto their sides and two of them remained upright after falling off the tracks, she said. No injuries were reported.

Scarano said a couple of gallons, at most, leaked, most likely from residue oil that spilled onto the seals of some of the tank car covers when the cars were filled up with oil.

"From what we see now, there's no leaking," she said from Pan Am headquarters in Billerica, Mass.

Department of Environmental Protection spokeswoman Samantha Warren said DEP crews who were at the derailment site were reporting very little leaked oil and catching it in pails placed under the tank car covers.

The derailment took place about 300 feet from the Penobscot River, she said.

"It's being measured in drips and not gallons," she said.

Oil from the derailed cars will be transferred to empty tank cars before the cars are and lifted up and put back on the tracks, Scarano said.

In November 2011, trains began carrying unrefined crude oil from the North Dakota oil field to the Irving oil refinery in Saint John, New Brunswick, Warren said.

The shipments have been increasing monthly, rising from about 1 million gallons in November 2011 to about 48 million gallons in December 2012. For all 2012, more than 220 million gallons of oil was transported across Maine, according to DEP records.

The growing volume of oil shipments has been a concern for the DEP, Warren said.

"We've been aware something like this morning's spill could be coming," she said.

Scarano said people shouldn't have worries about oil crossing the state by train.

"It's a safe way to transport it," she said.