Gunmen stormed into a drug rehabilitation center in the Mexican border state of Coahuila on Sunday, leaving 11 people dead. at least 10 others were wounded during the 9:30 p.m. the attack at the Centro de Rehabilitacion Tu Vida Sobre La Roca A.C. in the city of Torreon.

While extreme, attacks on rehab centers are not an uncommon facet of Mexico's six-year-old drug war. A worker at a drug recovery center Ciudad Juarez told Reuters that drug traffickers sometimes seek shelter in the centers, opening up the facility to the threat of retribution from rival cartels. Almost exactly one year ago, 13 people were killed in a different facility in Torreon, and one year earlier, more than 20 men armed with automatic weapons killed 19 patients at the Faith and Life drug clinic in the city of Chihuahua.