The U.S. Navy says it and British forces have seized more than 20 tons of drugs smuggled along a "hash highway" through the waters of the western Indian ocean.

The Navy estimates the narcotics seized since October — mostly hashish — are worth $100 million. It said proceeds could have helped fund militants in Afghanistan.

The seizures occurred in the Arabian Sea and Gulf of Aden along a route the Navy calls the "hash highway" in a Monday statement. The area is also the frequent scene of attacks by Somali pirates.

Navy 5th Fleet spokesman Lt. Nathan Christensen would not say where the drugs originated. But he says many of the narcotics along the route are going "to and from Afghanistan and Pakistan."