A D.C. high school teacher who was arrested last week on a child pornography charge has admitted to sending sexually explicit text messages to approximately 10 students during his career, according to court documents.

Police and the FBI began investigations into John Solano, a 29-year-old science teacher at McKinley Technology High School, after receiving a complaint that he was engaging in inappropriate sexual conversations with students.

Officers interviewed two McKinley students who said that Solano had sent them text messages about their bodies and masturbation. One male student said Solano sent sexually explicit photographs of himself and urged the student to do the same.

Confronted with those claims Friday at the FBI’s Washington Field Office, Solano admitted to sending the photographs and messages, the court documents say. He said he had engaged in similar conversations with no more than 10 other students.

The teacher has been placed on administrative leave, according to school system officials. He is due to appear in federal court Monday, according to documents.