The passengers are said to be migrants.
The Texas Department of Public Safety’s official Sgt. Nathan Brandley said that 20 people were injured and that several were in critical conditions, undergoing treatment at nearby hospitals.
The driver of the vehicle was killed in the crash.
Officials said the one-vehicle crash took place about 4 p.m. on northbound U.S. Highway 281, south of the Falfurrias U.S. Border Patrol checkpoint.
The van was transporting 30 people when it crashed south of Encino.
Northbound traffic was being diverted onto the FM 1017 exit.
Officials urged drivers to proceed with caution in the affected area.
The Department of Public Safety was working with the Mexican consulate and U.S. Border Patrol to know the identities of the victims in the crash.