HOUSTON - Five people were killed and two others were injured in a rear-end collision between two trucks in the US state of Texas Sunday, authorities said.

Officials from Texas Department of Public Safety said the accident happened early Sunday morning on a road near Seagraves in west Texas. A pickup carrying two people struck the rear of another truck carrying five, causing both to overturn. After rolling over, the vehicles came to rest in a roadside ditch.

Five of the seven died at the scene while the other two were taken to a hospital. Their conditions were unknown.

It is yet to be determined what exactly caused the crash, but officials said alcohol might have played a role. It was also reported that none of the seven people were wearing seatbelts at the time of the accident.

According to figures released by Texas Department of Public Safety, alcohol is the main cause of over 35 percent of all fatal crashes in the Lone Star state.