A gym teacher in Puerto Rico faces federal charges for allegedly using social media to entice a 15-year-old girl into unlawful sexual conduct.

The U.S. Immigration and Customs Enforcement agency on Monday identified the man as 27-year-old Melvin Rivera Gonzalez. He works at an elementary school in the northern town of Toa Baja.

The agency is handling the case under an initiative to track down sex predators.

U.S. agents say they began investigating Rivera after school officials reported he was using the popular Kik application for messaging and sharing video on smartphones to sexually entice a student. Agents allege he later engaged in sexually explicit conversations with an undercover agent posing as a minor.

A judge ordered Rivera held. It wasn't immediately clear if he has a lawyer.