BOGOTA, July 13 (Reuter) Police in northern Colombia seized 17 tons of marijuana that had been stashed in powdered milk cans for shipment to the United States, authorities said on Sunday. A police spokesman said the marijuana was torched on Saturday after it was discovered hidden in a junglecovered area of the Tayrona nature reserve near the Caribbean port of Santa Marta. The marijuana was apparently going to be dumped by speedboats off Colombia's coast and then picked up by larger vessels that were set to smuggle it into the United States, the spokesman said. 13:59 071397