VICTORIA, Texas (AP) _ Sheriff's deputies searching a tractor-trailer rig in South Texas early Wednesday found 16 people dead inside.

Victoria County Sheriff's deputies made the discovery about 2 a.m. after a reported disturbance inside a trailer at a truck stop near Victoria, said Stuart Posey, an investigator with the sheriff's department.

It wasn't immediately clear how many people were in the back of the tractor-trailer when it was opened or how long they had been there, Posey said. Victoria radio station KTXN reported that about 50 people were inside and 12 were hospitalized, including two in intensive care.

Federal immigration agents were headed to the scene, Posey said.

The truck stop is along Highway 77, about 230 miles from the Mexican border.