The family of a teenager who says she was punished by her South Texas school for refusing to recite the Mexican pledge of allegiance has filed a federal lawsuit claiming her constitutional rights were violated.

The lawsuit said Brenda Brinsdon was a high school sophomore in 2011 when her teacher told students to stand for the pledge of allegiance and to sing the Mexican national anthem.

It said Brinsdon's teacher and principal tried to "coerce" her when the girl declined to participate. The lawsuit was filed Wednesday in McAllen.

McAllen school district spokesman Mark May said Thursday the class was conducting a "cultural-awareness assignment."

May said students each day pledge allegiance to the United States and Texas, and they're not directed to offer a pledge to any foreign country.