SEATTLE — Environmental crews worked Saturday to contain a sheen of oil that appeared in the Columbia River along the Washington-Oregon border after a Union Pacific train derailed and caught fire, but officials said there was no immediate indication of harm to wildlife.

Sixteen of the 96 tank cars on the train derailed Friday near Mosier, Oregon, 70 miles east of Portland. Four burned, sending a thick plume of smoke into the sky before firefighters were able to extinguish the flames a little after 2 a.m. Saturday.

An aerial view provided by the Washington State Department of Ecology shows scattered tank cars Saturday following a derailment near Mosier, Ore., Friday. The Associated Press

No injuries were reported.

There was no immediate word on the cause of the derailment, which forced the evacuation of about 100 people from a nearby mobile home park. Officials said they would consider lifting the evacuation order Saturday night.

“I want to apologize to the community,” Union Pacific spokeswoman Raquel Espinoza said, adding that the company would pick up the tab for the response costs. “This is the type of accident we work to prevent every day.”

The derailment, in the scenic Columbia River Gorge, manifested the fears of environmentalists who have long argued against shipping oil by rail – especially through populated areas or along a river that’s a hub of recreation and commerce. The tank cars were carrying especially volatile crude from the Northern Plains’ Bakken region, which has a higher gas content and vapor pressure than other types of oil.

More than 100 people rallied and marched in nearby Hood River, Oregon, on Saturday to call for a halt to the practice.

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