The leader of a Mexican drug gang suspected in the disappearance of dozens of college students last month killed himself Tuesday after a gun battle with federal police, authorities said.
Mexico's attorney general later said that 28 bodies discovered in a mass grave do not belong to any of the students, who disappeared after a confrontation with police in the city of Iguala.
The whereabouts of the 43 missing students are still unknown, said Atty. Gen. Jesus Murillo Karam, adding that authorities also do not know the identities or fate of the people found in the grave.
Dozens of police officers from Iguala and the nearby town of Cocula have been arrested and reportedly have admitted to taking part in the abduction of the students. Prosecutors allege that police abducted the students and then leaders of Guerrero Unidos cartel ordered them killed.
Authorities said Mondragon first negotiated for the safe exit of a pregnant woman he was with at the time.
"When he saw that there was no escape, he shot himself," Ponce said.
Prosecutors accuse Mondragon's gang, which is believed to specialize in the transport of marijuana and heroin to Chicago, of working with local authorities on the night the 43 freshmen from a rural teaching college went missing.
The recent events have highlighted the close ties between local authorities and organized crime in towns across Guerrero, one of Mexico's most dangerous states.
Protesters angry over the events in Iguala have held violent demonstrations in recent days. On Monday, hundreds of people clashed with riot police and set fire to the Guerrero government headquarters in the state capital, Chilpancingo.
According to local media reports, protesters were gathering again in Chilpancingo on Tuesday afternoon. Some reportedly had come from universities in other parts of Mexico to register their anger at the violence against students.