Three teens, one a U.S. citizen, have been killed in the Mexican border city of Ciudad Juarez, a spokesman with the Chihuahua state prosecutor's office has said

The killing was the first case in 2011 of an American student being killed in Juarez, which has been beset recently by violence and is just across the border from El Paso, Texas, spokesman Arturo Sandoval said. The shooting happened at a car dealership, where the teens were looking at cars, according to Sandoval. Police recovered at least 18 bullet casings at the scene from an AK-47, an automatic weapon commonly used by drug traffickers in the city. Two of the victims were born in Ciudad Juarez and were identified as Carlos Mario Gonzalez Bermudez, 16, and Cesar Yalin Miramontes Jimenez, also 16, according to Sandoval. The other victim, identified as Juan Carlos Echeverri Jr., 15, was born in El Paso, the prosecutor's spokesman said. The teen's parents have identified his body and confirmed that he was an American citizen. Virginia Staab, a spokeswoman for the U.S. State Department, said that U.S. authorities are actively looking into the incident and had not yet confirmed the citizenship of any of the victims.