Mexican authorities have discovered another mass grave in the state of Guerrero.

Investigators found the grave site while scouring the area for nearly four dozen students who disappeared last month.

Their loved ones fear the worst -- as days pass with still no answers about their children's whereabouts.

Federal authorities have arrested more than 50 people in connection with the students' disappearance, including dozens of police and gang members.

Details about this mass grave site are still emerging.