A fitness instructor in the small town of San Luis Potosi, Mexico, is accused of raping and murdering four young girls and one woman, and then dumping their bodies in fields, according to authorities.

The alleged serial killer, Filiberto Hernandez, was arrested on Saturday. He has since confessed to the five murders between 2010 and 2013, according to the state attorney's office in San Luis Potosi.

After Hernandez's arrest, the police identified three of Hernandez's victims; Adriana Martinez, a 32-year-old factory worker who disappeared in May, 9-year-old Dulce Jimena Reyes who disappeared about two months ago, and Adriana Martinez, 13, who whose body was found three years ago after she went missing on her way from school.

Officials are now searching for the bodies of Hernandez's two other victims, 16-year-old Rosa Maria Sanchez, who has been missing since 2010 and 12-year-old Itzel Castillo, who disappeared in 2013. Authorities are searching fields in close proximity to where the previous bodies were found. 

Hernandez was a Zumba instructor and karate teacher in the small town prior to his arrest.