Mexico's government says it's "profoundly worried" by the killing of a Mexican migrant who was shot last week by a U.S. Border Patrol agent in Arizona. The Foreign Relations Department said in a statement Thursday that it has asked for a thorough investigation into the slaying of Gabriel Sanchez Velazquez.

Federal authorities in the United States and Mexico said they'd located an unfinished smuggling tunnel this week during a border sweep in Nogales, Ariz. The unfinished tunnel originates in Mexico and extends 133 feet into the United States, U.S. Customs and Border Protection said in a statement.