Fifteen Mexican police officers have been killed and five seriously wounded in the deadliest single attack on the country’s security forces in recent memory.

The officers’ convoy was ambushed as it drove along a winding mountain road in the western state of Jalisco on Monday afternoon.

The gunmen, believed to belong to the New Generation Jalisco cartel, reportedly used burning vehicles to block the road while they openend fire with machine guns and grenade launchers from the mountainsides.