Arkansas State Police said in a statement they were called to the site about 3 a.m. Sunday in Hoxie.
Union Pacific spokesman Brandon Morris says two cars caught fire, one carrying diesel and one carrying an alcoholic beverage. He says the fire was out about 10 a.m.
Arkansas Department of Emergency Management spokesman Kendell Snyder said no health hazards had been detected from the fire.
The Lawrence County Sheriff’s Office said about 500 people were forced to leave their homes, but emergency officials say most were allowed to return by midmorning.
In June 2012, a head-on train crash in the Oklahoma Panhandle killed three Union Pacific crewmembers.