NEW : U.S. Embassy says the wounded Mexican Marines are in stable condition . Mexican Marines say U.S. Embassy opened fire on the Federal Police vehicle . Mexico City ( CNN ) three embassy employees -- said to be Mexico City citizens -- were wounded .
NEW : U.S. Embassy says the wounded Mexican Marines are in stable condition . Mexican Marines say U.S. Embassy opened fire on the Federal Police vehicle . three embassy employees -- said to be Mexico City citizens -- were wounded .