HERMOSILLO, Mexico (AP) — Drug trafficers are using an medieval invention as a new way to move marijuana and cannabis across the border from Mexico to Arizona.

The discovery of two "drug catapults" in the Mexican state of Sonora marks the latest twist in the cat-and-mouse game smugglers play with the us border patrol. US National Guard troops operating a remote surveillance system at the Naco Border Patrol Station say they observed several people preparing a catapult and launching packages marijuana over the fence.

A Mexican army officer says the three-metre tall catapult was found about 20 meters from the US border on a flatbed towed by a sports utility vehicle. The officer says the catapult was capable of launching 2 kilogrammes (4.4 pounds) of marijuana at a time. He says soldiers seized 16 kilogrammes ( 35 pounds) of weed, the vehicle and the catapult.

The drug trafficers left before they could be arrested. The surveillance dvd of them using the catapult was released Wednesday. Near Agua Prieta , another border town. A second catapult was discovered.