MEXICO CITY, Oct. 28 (UPI) -- Mexico's Attorney General Jesus Murillo Karam announced Monday that a new mass grave has been discovered in Guerrero state as investigators search for 43 missing university students.
It is unclear what led investigators to the mass grave near a landfill in Cocula, approximately 30 miles from the town of Iguala where the students were last seen clashing with local police on Sept. 26.
DNA testing is being conducted on the remains.
Hours after the discovery, federal authorities arrested four members of the Guerreros Unidos gang for conspiring with local police to kidnap the students.
"We have the people who carried out the abduction on these individuals," Karam told reporters. Two of the gang members, Karam noted, confessed to involvement in the forced disappearance, admitting they had "received a large group of people."
Federal authorities have so far arrested 56 people, mostly local police, in connection with the students' disappearance. Karam has condemned Guerrero state for its "network of complicity" between drug cartels and police departments.
Mexican officials issued arrest warrants on Oct. 23 for Iguala Mayor Jose Luis Abarca and wife Maria de los Angeles Pineda, who authorities believe were the "probable masterminds" in the attack. According to the attorney general, the couple wanted to get rid of the students because they didn't want the students' protest to disrupt a planned political event hosted by Pineda in the town the same day.
The couple have since disappeared and are believed to be on the run.
The search for the missing students has resulted in the discovery of 19 mass graves in the vicinity of Iguala. DNA testing confirmed that 28 bodies found in one of the mass graves were not those of the missing students. DNA testing on remains found in the other graves is ongoing.
