Twenty-six bodies were discovered bound and gagged on Thursday in vehicles abandoned in the heart of Guadalajara, Mexico's second-largest city and the site of the recent Pan American Games, officials said. Best known as the home of mariachi music and tequila, this picturesque city has also been the historic base for methamphetamine trafficking by the powerful Sinaloa cartel. The cartel's tight grip on the city was shattered by the death of its regional commander, Ignacio "Nacho" Coronel, in a shootout with federal police in July 2010. Guadalajara's murder rate then soared as factions of the cartel known as the New Generation and the Resistance battled to control Coronel's territory and assets. Street battles have left hundreds dead in the city and surrounding areas. Security officials have said they feared that the chaos could provide an opening for the Zetas drug cartel, which has been using paramilitary-style tactics and headline-grabbing atrocities in a national push to seize territory from older organized crime groups.