4 Americans missing after being kidnapped in Mexican border city, FBI says

Read MoreThe agency says their vehicle was fired on after it entered Matamoros. The city, home to warring Gulf drug cartel factions, was the scene of several shootouts late last week.The agency says their vehicle was fired on after it entered Matamoros. The city, home to warring Gulf drug cartel factions, was the scene of several shootouts late last week.