ADDIS, La. (AP) — Four chemical tanker cars derailed in Louisiana on Tuesday, prompting emergency officials to order a precautionary overnight evacuation of two nearby subdivisions.

The cars derailed in the West Baton Rouge Parish town of Addis about 1:30 p.m., news media outlets quoted authorities as saying.

The rail cars belonged to various companies but were being pulled by Union Pacific, said Addis Police Chief Ricky Anderson.

Union Pacific spokesman Jeff DeGraff told The Associated Press that the derailment happened as the train was switching to a different track on its way out of the Addis railyard.

DeGraff said there were no injuries and no leaks from any of the cars, two of which were carrying propylene oxide and dichloropropane, respectively, hazardous flammable liquids that he said are often used in making plastics. A third car was carrying a sodium hydroxide solution while a fourth was carrying a nonhazardous glycol residue, DeGraff said.

Authorities were also quoted as saying that there were no leaks, and that evacuations were ordered as a precaution.

West Baton Rouge Parish spokeswoman Lynn Cline said evacuations were ordered at 175 to 200 houses within 1,000 feet of the track where the cars derailed. WBRZ-TV reports (http://bit.ly/1FyDohE ) that residents outside the area were ordered to stay inside their homes until the evacuation is lifted, possibly by Wednesday morning.

Authorities believe the derailment was caused by damaged tracks and not operator error, Anderson said.

DeGraff said Union Pacific officials also suspect the derailment was "rail-related," but were still investigating. Workers were trying to get the toppled cars righted late Tuesday, DeGraff said. He said the hope was to have "everything back up and running" by Wednesday morning.