Three men were arrested and a 481-foot drug tunnel in Nogales, Ariz., was shut down by federal authorities Monday night.

A multiagency investigation led to the discovery of the tunnel, which is the longest found in the border city, according to a U.S. Immigration and Customs Enforcement news release. Authorities seized more than 640 pounds of marijuana and a half-pound of heroin during the operation.

Taken into custody were Jesus Alberto Ramirez-Valencia, 22, of Nogales, Ariz.; and Jose Solorzano-Flores  and Jose Mario Armenta-Valdez,  both 41, of Mexico, the release said.

The men are facing drug conspiracy charges.

According to the news release, the tunnel runs between private residences in Nogales, Ariz., and Nogales, Sonora, and stretches 411 feet on the U.S. side from the U.S. entrance to the international border. and extends another 70 feet into Mexico.

The passageway is about 2 feet wide by 3 feet tall, and contains wood shoring, electric lighting and fans to circulate air.