CIUDAD VICTORIA, Mexico (AP) — Officials say at least nine workers are dead and seven more injured after a big-rig truck and a factory bus collided in northern Mexico.

The Tamaulipas state prosecutor's office reports that the crash took place Thursday on a highway between the cities of Reynosa and Matamoros, along the Texas border.

The accident involved a double tractor-trailer loaded with grain and a bus carrying employees of the Invamex factory in Reynosa.

Authorities said Friday that one of the trailers apparently fishtailed into oncoming traffic and struck the bus.

The truck driver is suspected of speeding and has been detained.