The American Civil Liberties Union of Pennsylvania alleged Monday that Quakertown Police Chief Scott McElree violated his commitment to “serve and protect” his community during last week’s student walkout at Quakertown Community High School.

Friday’s protest against U.S. Immigration and Customs Enforcement actions led to a confrontation between police and students, culminating in the arrest of five teens and one adult.

“By all accounts, including abundant video evidence, there were no issues at the demonstration until Quakertown police arrived and incited violence,” Witold Walczak, legal director of the ACLU of Pennsylvania, said in a statement.

WHYY News reached out to the borough and the police department for comment. A police administrator sent a brief statement.

“Quakertown Borough and the Quakertown Police Department are fully cooperating with the Bucks County District Attorney’s Office concerning this investigation,” the statement reads. “Until this investigation is complete, neither the Borough nor its Police Department will be commenting on this matter.”

About 30 students participated in the walkout Friday, after the school district canceled a planned walkout that day. Videos showed officers wrestling students to the ground.