MEXICO CITY (AFP) - At least 16 people were killed on Thursday when a bus overturned and caught fire in northwestern Mexico, local authorities reported.

The bus was bound for the northern border city of Tijuana when it crashed on a road in Ciudad Obregon, the head of the state of Sonora's civil protection agency said.

"What we know at the moment is that the bus overturned and caught fire and that 16 fatalities were recovered," civil protection chief Carlos Jesus Arias said.

He said 20 people were taken to area hospitals to be treated for injuries.