Investigators are working to identify a charred body found Tuesday in the sleeper cab of a burning semi truck near Tucumcari.

The state medical investigator will determine identity and cause of death, according to a press release from the New Mexico Department of Public Safety.

Motor Transportation police officers responded to a report of a truck on fire around 3 a.m. on Interstate 40 near mile marker 369, the release said.

When the fire was extinguished, a burned body was found in the sleeper area of the semi.

The highway was closed for an hour because of the fire, the release said.