From Fox News:

U.S. agents on assignment in Mexico, where they are helping the local authorities go after violent drug cartels, are not allowed to carry weapons for their own protection, a situation that one lawmaker says could turn into “another Benghazi.”

President Obama gave tacit approval to Mexico’s prohibition against U.S. agents carrying weapons in March 2011, following the ambush killing of ICE agent Jaime Zapata and the wounding of his partner, Victor Avilla.