A crash involving the Heartland Flyer train was reported Friday night in Love County, the Oklahoma Highway Patrol said.
The crash happened shortly after 7 p.m. Friday near Highway 77 and Addington Bend Road.
A semi car hauler reportedly got stuck on the tracks and was hit by the train.
The train was going to Norman, Oklahoma, from Fort Worth, Texas.
Paramedics are checking customers for injuries after the train made a hard stop.
Four people from the train were taken to a local hospital, the Love County sheriff's office said.
Authorities are investigating the crash and are asking motorists to avoid the area if possible.
Troopers said the train did derail a bit. NTSB will handle the majority of the investigation.
Amtrak released the following statement:
"Amtrak Train 822 struck a truck that was on the BNSF Railway tracks near Thackerville, Okla., at approximately 7 p.m. CT this evening. There were approximately 110 passengers and crew members onboard, with four passengers transported to a local hospital with minor injuries. Local authorities are investigating.
"Train 822 operates daily between Fort Worth and Oklahoma City."