TECATE, Mexico (AP) — The Mexican army says it has found a new tunnel dug by drug smugglers under the border with the United States.

The army says it found the tunnel under construction in a water-purification plant in Tecate, across the border from a mostly rural area of Southern California.

Soldiers arrested eight people during the operation and confiscated a small amount of marijuana.

The tunnel was about five feet in diameter and 135 yards long, with a concrete floor and ventilation and electric lighting.

U.S. and Mexican authorities have discovered a series of similar border tunnels in recent years.

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