BOSTON (AP) -- Boston federal prosecutors have filed a child pornography charge against a Cambridge fifth grade teacher they say acknowledged secretly videotaping children changing clothes, including in a locker room.

The U.S. attorney's office said 27-year-old Josh Wairi of Somerville was arrested Thursday and charged with transportation of child pornography.

A postal inspector's affidavit doesn't say where the videotaping occurred. It alleges Wairi received child pornography by email, and uploaded images and videos of children being sexually exploited that he transferred to others.

Wairi is held until a hearing Wednesday. It's not immediately known who is representing him.

Cambridge School Superintendent Jeffrey Young said he feels "shocked and betrayed," and apologized to parents. He said Wairi has been placed on administrative leave and the district is cooperating with investigators. Community meetings are planned at the school.