CIUDAD JUAREZ, Mexico (AP) - U.S. and Mexican officials say they're looking into why a suspected drug gang ambushed two cars carrying families with ties to the U.S. consulate in a Mexican border city over the weekend -- killing an American couple and a Mexican man.

Three young children survived. Two of them were wounded.

An FBI spokeswoman in Texas says there's no indication that they were targeted because of their work with the consulate in Ciudad Juarez.

Mexico's federal Attorney General's Office says it's taking over the case from local authorities. The FBI says it's aiding Mexican investigators.

Officials say the SUVs were carrying the families of U.S. consular employees from a children's party.

Several U.S. citizens have been killed in Mexico's drug war, most of them people with family ties to Mexico. It is very rare for American government employees to be targeted.

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