A train carrying toxic chemicals derailed in Tennessee and caught fire, prompting a large-scale evacuation, fire fighters said Thursday.

The train derailed near Maryville, close to the city of Knoxville, carrying acrylonitrile, a flammable, toxic compound that poses respiratory risks, firefighter Kermit Easterling said.

Some 5,000 residents are being evacuated, and firefighters are going door to door wearing breathing equipment to get people away from the fire, he said.