Police Hunt for Teacher Who Fled With Boy, 13

Authorities are searching for a female teacher from Nebraska who they say kidnapped a 13-year-old former middle school student with whom she had a relationship.

A warrant for Kelsey Peterson's arrest was issued after investigators filed an affidavit indicating that the woman had an ongoing relationship with 13-year-old Fernando Rodriguez that could be traced to her job at the Lexington Middle School.

(Lincoln Police Department)

"Right now, there's a warrant we got for the arrest of Kelsey Peterson for kidnapping, child abuse and contributing to the delinquency of a minor," said Paul Schwarz, a criminal investigator for the Lexington, Neb., Police Department, to ABC News.

The parents of Fernando Rodriguez reported their son missing Saturday after he was last seen late Thursday. A warrant for Peterson's arrest was issued after investigators filed an affidavit indicating that the woman had an ongoing relationship with Rodriguez that could be traced to her job at the Lexington Middle School.

Peterson, 25, has been on administrative leave from her sixth-grade teaching and basketball coaching positions because of her relationship with Rodriguez, Schwarz said.

In the five days since the pair were last seen, they've been tracked to Denver and then closer to home in Nebraska. They have also been in touch with their respective families, Schwarz said. "Right now, both families have been very cooperative," he said.

While the boy may not be in any immediate physical harm, authorities remain anxious to return him to his family.

"We do have some concerns because she's restraining his freedoms," Schwarz said. "Our largest concern at this point is that they're going to continue to evade police and continue whatever type of relationship they have."

It's unclear whether the relationship between the two is sexual in nature, but police confirmed that the teacher and student had exchanged several letters in the last year.