MEXICALI, Mexico - Police in the border city of Mexicali say they have recovered a powerful improvised cannon used to hurl packets of marijuana across a border fence into California.

Police told the Televisa network that the device was made up of a plastic pipe and a crude metal tank that used compressed air from the engine of an old car.

The apparatus fired cylinders packed with drugs that weighed as much as 30 pounds, police. It was confiscated last week after U.S. officers told Mexican police that they had been confiscating a large number of drug packages that appeared to have been fired over the border. Mexican police on the border have recovered a series of similar devices in recent years.