From [HERE] A high school student in Houston, Texas, is accusing resource officers of using excessive force to detain her after she refused to give up her cell phone to a school administrator Tuesday.

Ixel Perez, a 15-year-old girl, says three officers at Sam Houston Math, Science and Technology Center tackled and handcuffed her in order to take the phone away. One officer used his knee to press down on her head as she screamed in pain, she said. An onlooking student recorded video of the incident, which was later posted on Instagram and shared widely on other social networks.

Sheleah Reed, a spokesperson for the Houston Independent School District, told BuzzFeed administrators and the school district’s police department are investigating the incident “to find out exactly what led to the student’s detainment.” She said student safety was a top priority for all schools in the district, but did not provide any further details pending the investigation.

Some of the school’s students and parents organized a rally Wednesday to denounce the officers’ actions and posted pictures on social media using the hashtag #Freesamhouston.

At the rally, Perez told local reporters her reading teacher caught her checking her phone, against school policy, and kicked her out of class. Perez said she refused to give up her phone to the school’s assistant principal because her stepfather had texted to say he couldn’t locate her mother, who has kidney problems and received dialysis.