The Mexican army says its fight against surging opium production that feeds U.S demand is increasingly complicated by the rise of smaller gangs disputing wild, ungoverned lands planted with ever-stronger poppy strains.

The gangs have engulfed the state of Guerrero in a war to control poppy fields, turning inaccessible mountain valleys of endemic poverty and famous beach resorts into Mexico’s bloodiest spots.

From this frontline of the fight against heroin, Col. Isaac Aaron Jesus Garcia — who runs a base in one of the state’s most unruly cities, Ciudad Altamirano — sees a direct link between a record U.S. heroin epidemic that killed nearly 13,000 people in 2015 and violence on his patch.

Heroin use in the United States has risen fivefold in the past decade, and addiction has more than tripled, with the biggest jumps among whites and men with low incomes. (Reuters)

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