A Mexican official said Saturday that forensic experts had identified at least one of the 43 missing college students among charred remains found in a garbage dump and river in Guerrero.
The official did not give any details.
The 43 students disappeared in September from the city of Iguala after confrontations with police that also left several others dead. Authorities believe Iguala's mayor, Jose Luis Abarca, and his wife ordered police to round up the students and turn them over to a local drug gang.
Gang members allegedly murdered them, burned the bodies, and threw the ashes into the river and dump.
The mayor, his wife, and a number of officers and drug gang members have been arrested.
The grisly case has infuriated Mexicans who say they are sick of corruption, and it has shaken President Enrique Pena Nieto, whose government is accused of waiting too long to investigate.
The killings have led to large protest marches in Mexico City, where demonstrators have demanded that Pena Nieto resign.