ROUGH CUT (NO REPORTER NARRATION)<br/> <br />Parents defending three schools in Oaxaca, Mexico faced off with striking teachers protesting against President Enrique Pena Nieto's approved reform of the country's education system.<br/> <br />Standing on the schools' rooftop in the municipality of Pueblo Nuevo, parents - some of them acting as teachers to replace striking teachers - tried to defend installations from being taken over by protesting teachers a month after Pena Nieto signed a controversial law to overhaul the education system.<br/> <br />The reform seeks competency exams, merit-based promotions and aims to tame a powerful teachers' union many blame for hurting school quality in Latin America's No. 2 economy.<br/> <br />Mexico's record on student achievement is one of the worst among countries of the Organization for Economic Co-operation and Development.
