A former elementary school volunteer was indicted on additional federal child pornography charges Monday, part of a continuing investigation into a wide-ranging child-sex abuse case in Prince George's County.

Deonte Carraway, 22, faces 13 federal charges of sexual exploitation of a minor to produce child pornography, according to court documents.

A federal grand jury charged that Carraway persuaded children to engage in "sexually explicit conduct," recorded the acts and transmitted the material to others, the documents state. The documents indicate that Carraway had the children perform sex acts on him and on each other.

Carraway, of Glenarden, Md., was arrested Feb. 4. He admitted creating videos showing children between the ages of 9 and 13 performing "vile sexual acts," according to police.

Carraway faces separate criminal charges in Prince George's County, where police have determined that 17 children are victims in the case.

Prince George's police are working with the FBI, and the 11 victims cited in the federal indictment are part of the group of 17 children that county law enforcement determined are victims.

Carraway abused children and had created about 40 videos of them since at least January 2014, according to police. The abuse occurred in private homes and at the Glenarden Municipal Center, the Theresa Banks Memorial Aquatic Center, Zion Praise Tabernacle Lutheran Church and Judge Sylvania W. Woods Elementary School — where Carraway was a volunteer, police said.

Some of the abuse occurred during the school day and on school grounds, police said.

The case has left many parents upset, with questions about how a library volunteer charged with shelving books two days a week was given unsupervised access to students.

County school system officials have created a task force to review policies and training at the elementary school and will retrain employees on procedures for reporting suspected abuse.

The principal was placed on administrative leave as a precautionary measure and the school has been offering counseling to students, school officials said.

"We have pledged our support to the victims and their families, and the safety and welfare of students remains a top priority," school officials said in a previous statement.

Carraway communicated with many of the students through Kik, an anonymous messaging app, police said. A federal complaint filed last week said Carraway distributed phones to students to communicate with them.

In one case, Carraway pulled a boy from class to a dressing room and told the student to pull off his own pants. When the boy refused, Carraway threatened to call the police and the principal, the federal complaint states.

Each of the federal charges carries a mandatory minimum sentence of 15 years in prison. Carraway, who is in jail on $1 million bond on the local charges, is scheduled to appear in federal court Friday.