Sixteen people were killed and four others injured Monday when a van collided with a tractor-trailer in the northern Mexican state of Sonora, authorities said.

The van was headed southbound on the Caborca-Sonoyta highway and apparently strayed into the northbound lane, striking the truck head-on, state police said.

Killed were the driver of the truck, Jose Luz Oliven, 55, and a 10-year-old boy accompanying him, as well as 14 people traveling in the van.

Four other people in the truck, including two young children, survived with injuries and were taken to a hospital in Caborca, police said.

Mexico averages around 24,000 traffic fatalities a year.

An April 20 crash in the Gulf coast state of Veracruz left 43 people dead and 27 injured.

That accident involved a bus and a tractor-trailer. EFE