A Mexican students’ association in the western city of Guadalajara has denied any involvement in the killings of five people found buried at its headquarters and said it will work with authorities to help them solve the case.

“The FEG (Federation of Guadalajara Students), as an institution, has no connection to these crimes,” the head of the student group, Israel Mariscal, told a radio station Friday.

Four students aged 16-21 and the father of one of the youths were found dead between Wednesday and Thursday in clandestine graves at the FEG’s headquarters days after the University of Guadalajara had reported them missing.

The five had allegedly gone to the FEG’s offices near downtown Guadalajara to demand that the student group lower the fee they were charging a snack vendor, the oldest victim, for permission to sell churros (a fried-dough dessert) outside a school.