The U.S. Embassy and Consulates in Mexico have issued a new warning to visitors of Cancun and the Mexican state of Quintana Roo over a potential conflict between taxi drivers and ride-hailing service companies. Medallion taxi drivers have been attacking ride-hailing service drivers as they battle over lucrative tourist rides. Unfortunately, passengers have been caught in the middle. “Official complaints against Uber and other drivers do occur … and past disputes between these services and local taxi unions have occasionally turned violent, resulting in injuries to U.S. citizens in some instances,” the warning reads. On Monday, taxi drivers blocked Kukulcán Boulevard — one of the main roads to the hotel…