One man was detained for questioning, Wilson County Sheriff's Office Captain Scott Moore told FOX17. A minor was in the vehicle.
Police have blocked off a section of Highway 231S in Lebanon, Tennessee, while investigating a white box truck nearby.
It's not clear if the truck was connected to the RV that exploded in downtown Nashville on Christmas Day.
"Highway 231 South from the Cedars of Lebanon State Park to Richmond Shop road is currently shut down due to a suspicious vehicle. Please avoid the area and seek an alternate route. We will post updates as more information comes in," the office wrote.
A reporter from WSMV in Nashville said on a live broadcast that the truck allegedly played the same audio as the one played before the RV exploded. Officials said earlier in the day that the Nashville RV was playing "Downtown" by Petula Clark before the blast.
The FBI, the Tennessee Highway Patrol, and Wilson County Sheriff's deputies are investigating the box truck in Murfreesboro.
Over the weekend, the FBI and other law enforcement agencies searched a home following the Christmas Day blast, which occurred near an AT&T building downtown. A motive for the incident was not revealed, and a suspect hasn't been identified.