LYNDEN, Wash. (AP) - Federal agents have shut down an elaborate, 360-foot drug-smuggling tunnel dug underneath the U.S.-Canadian border - the first such passageway discovered along the nation's northern edge, officials said Thursday.

Five people were arrested on marijuana trafficking charges, U.S. Attorney John McKay said in this border town about 90 miles north of Seattle.

The tunnel runs from a quonset hut on the Canadian side and ends under the living room of a home on the U.S. side, 300 feet from the border. Built with lumber, concrete and metal reinforcing bars, the passageway was equipped with lights and ventilation, and ran underneath a highway.

"They were smart enough to build a sophisticated tunnel. They weren't smart enough to not get caught," McKay said.

McKay said authorities had been monitoring construction of the tunnel for six months and sealed it shortly after it opened Wednesday.

Although numerous smuggling tunnels have been found on the U.S.-Mexican border, this was the first discovered along the border with Canada, McKay said. Canadian authorities learned of the tunnel in February and alerted U.S. officials.

Francis Devandra Raj, 30; Timothy Woo, 34; and Johnathan Valenzuela, 27, of Surrey, British Columbia, were arrested Wednesday. They were charged with conspiracy to import and distribute marijuana. Raj owns the property under the quonset hut, authorities said.

On July 16, two other people were arrested separately in Washington state for transporting marijuana that had come through the tunnel, said Greg Gassett, a Drug Enforcement Administration agent.

One was a woman who authorities said had 93 pounds of marijuana in her vehicle when she was stopped. The other was a man pulled over with 110 pounds of the drug.

On July 2, agents entered the home on the U.S. side to examine the tunnel. They later installed cameras and listening devices in the home.