SAN DIEGO (AP) — An estimated 14 tons of marijuana was seized after the discovery of a tunnel that the authorities said on Wednesday was one of the most significant drug smuggling passages ever found on the United States-Mexico border.

The tunnel stretched about 400 yards and linked warehouses in San Diego and Tijuana, Mexico, the authorities said.

The authorities in the United States seized 9 to 10 tons of marijuana on Tuesday inside a truck and at the warehouse in San Diego’s Otay Mesa area, said Derek Benner, Immigration and Customs Enforcement’s special agent in charge of investigations in San Diego. Mexican authorities recovered about five tons.