Nearly 10,000 gallons of latex used for coating paper in a paper mill spilled into the North Branch of the Potomac River in western Maryland, according to environmental officials.

The incident happened Wednesday at Luke mill in that area, according to Jay Apperson, a spokesman with the Maryland Department of the Environment. He said the latex spilled as it was being unloaded from a rail car.

The spill “discharged” through a collection system into the river, Apperson said. The mill is run by Verso Corporation, which is based in Memphis, Tenn.

The area where the latex spilled into the river is near the border of Maryland and West Virginia in Garrett County. It created a yellow-white look to the water, according to officials with the state’s environment department. The latex spilled into the river over a four-hour period.

The company’s mill employs about 800 people and sits on roughly 200 acres, about 25 miles from Cumberland. The Luke mill has the capability to produce nearly 500,000 tons of paper a year. There has been a mill in that area, according to the company’s Web site, since the late 1880s.

In an e-mailed statement, Kathi Rowzie — a spokeswoman for Verso — said it was an “isolated incident.” She said the mill is cooperating with the investigation.

Maryland officials said they have not seen any indication of fish being killed as a result of the latex spill in the area. As a precaution, however, authorities from the state’s Department of Natural Resources fisheries program were notified.

There is no threat to drinking water facilities in the area, according to Apperson. The incident remains under investigation.