Mexico City ( CNN ) -- Mexican federales were facing questioning Friday after authorities accused them of opening fire on a U.S. diplomatic vehicle south of the capital . Two U.S. Embassy employees -- described by a senior U.S. government official as U.S. citizens -- were taken to a hospital with non-life-threatening wounds ; a member of the Mexican Navy who was with them in the late-model Toyota Land Cruiser suffered light bruises , according to the Navy , which issued a statement giving the following account of events : . The incident unfolded at 8 a.m. , as the two embassy employees and the Mexican en route to a military facility in the municipality of Xalatlaco . Some 4 kilometers ( 2.5 miles ) earlier , they had left the main highway that connects Mexico City with Cuernavaca , near the town of Tres Marias , a thinly populated area off the main road . When a vehicle containing Federal Police approached and its occupants brandished their weapons , the driver of the diplomatic vehicle tried to evade them and return to the main highway . At that point , the police sprayed bullets into the black SUV with diplomatic plates . Moments later , three other vehicles carrying Federal Police joined the attack , also shooting at the U.S. Embassy vehicle . By now , the Mexican who was in the embassy vehicle had contacted personnel at a nearby military installation , who arrived after the firing had ended and cordoned off the site . Both embassy employees were taken -- under Federal Police guard -- to a hospital . Photographs of the SUV showed the embassy vehicle pockmarked with more than a dozen holes and at least three of its tires flat . The Federal Police officers involved were being questioned by authorities to establish what happened . They may be prosecuted . In a statement , the U.S. Embassy described the Mexican as a Navy captain and said the three individuals were en route to a training facility when they were ambushed . `` The vehicle attempted to escape , was pursued and sustained heavy damage , '' the statement said . `` They called for assistance from the Mexican armed forces , who responded . The two U.S. wounded personnel were taken from the scene , given medical treatment and are in stable condition . The Mexican Navy captain sustained no serious injuries . '' The Mexican government said those members of the Federal Police who fired on the vehicle have been detained , the statement said . It added that the Mexican government `` has stated it will conduct a full and thorough investigation of this incident . '' CNN 's Jill Dougherty , Rafael Romo and Terry Frieden contributed to this report .
NEW : U.S. Embassy says the wounded Americans are in stable condition . Mexican Marines say Federal Police opened fire on the U.S. Embassy vehicle . The shooting happened at about 12:30 a.m. local time, according to a statement from Mexico's Foreign Ministry.