A 7-year-old American girl is dead after Mexican police fired upon a pickup truck during a drug enforcement operation, the Tamaulipas state prosecutor's office confirmed Friday. 

The girl was traveling in a pickup truck with five other children when they spotted a Mexican police helicopter following them, according to the girl's mother, CBS News reported. 

The mother told Mexican media that the family stopped the truck, and her husband got out to signal to the police that they were civilians. Despite this, according to the mother, the police fired upon the truck anyway, and the girl was struck in the head. 

Prior to the girl's death, police had captured Alfredo Cárdenas Rodríguez, an alleged high-ranking member of the Gulf Cartel, KABB-TV in San Antonio reported. The arrest was followed by an escalation of violence in the area.