ARMED men killed a child and six others after storming a resort in the central Mexican state of Guanajuato, authorities said, in a region increasingly plagued by drug cartel violence. Footage widely shared on social media showed the aftermath of the attack in a palm-studded resort in the small town of Cortazar, about 65 km (40 miles) south of Guanajuato city. It was not clear who was behind the shooting that killed the seven-year-old, three men and three women, Cortazar's local security department said. One person was seriously injured in the La Palma resort. But in recent years rival drug…