Three large crosses lean against the burned out facade of Iguala's City Hall. Masked protesters angry about the disappearance of 43 students — attacked on orders of Iguala's mayor, according to Mexican federal authorities — burned the building last week. Carrie Kahn/NPR hide caption

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In Mexico City on Wednesday, people march to demand justice for 43 missing students. Mexican authorities ordered the arrest of the mayor of Iguala and his wife in connection with the attack. Yuri Cortez/AFP/Getty Images hide caption

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Students chant slogans in front of the Attorney General Office in Mexico City on Wednesday during a protest over the 43 students missing in Iguala, Guerrero State. Omar Torres/AFP/Getty Images hide caption

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Groups of rural and community police arrive in the city of Iguala on Tuesday to help in the search for 43 students who disappeared after a confrontation with local police on Sept. 26. Miguel Tovar/STF/LatinContent/Getty Images hide caption

itoggle caption Miguel Tovar/STF/LatinContent/Getty Images