13 killed in clash on Falcon Lake at U.S.-Mexico border

(CBS/AP) MEXICO CITY - Mexican marines patrolling Falcon Lake, which straddles the Texas-Mexico border, discovered a drug gang camp on an island, provoking a gun-battle that left 13 people dead, Mexico's navy said Monday.

Pictures: Falcon Lake Shooting

One marine and 12 suspected gunmen of the Zetas drug cartel were killed in the exchange Sunday on Falcon Lake, a dammed section of the Rio Grande which gained attention when U.S. citizen David Hartley was presumably chased and gunned down there by pirates last Sept. 30. 

At the time, he and his wife, Tiffany, were returning to Texas after photographing a historic church on the Mexican side of the lake. Hartley's body has not been found and Mexican investigators have reported no leads in the case.

In the gun-battle on Sunday, the Mexican navy said the drug gang opened fire first when the marines discovered the camp, which the gang is believed to have used as a launching point for smuggling marijuana into Texas by speedboat. Marines seized more than 20 guns after the shootout.

Complete coverage of the Falcon Lake shooting on Crimesider