Mexican authorities say 16 people were killed when a minivan crossed into approaching traffic and crashed head-on with a trailer truck in the northern state of Sonora, across the border with Arizona.

Sonora state prosecutors say in a statement that all 14 people traveling in the minivan died in the Monday morning crash on the Caborca-Sonoyta highway. They say the minivan burst into flames and the bodies have not been identified because they were badly burned.

Prosecutors say the driver of the trailer truck and his 10-year-old grandson traveling with him also died in the accident. Two adults and two children also in the truck were injured.