Police continue to investigate after four women on a rideshare bus on an Alabama university campus allege they were drugged by the bus driver.

Auburn police and Auburn University security said four women reported the incident Tuesday to the university’s security force.

The women apparently had used the rideshare bus to attend an off-campus function. The bus driver reportedly provided drinks to the women and the women said they became ill after drinking the beverages.

Police have not publicly identified the driver.