MEXICO CITY, Oct. 16 (UPI) -- Vigilantes searching for 43 students who disappeared Sept. 26 after clashing with police in the Mexican town of Iguala have discovered six new grave sites.
The discovery comes after DNA testing confirmed that human remains rule found in a mass grave outside the town were not those of the missing students.
At least two of the newly discovered graves appear to contain human remains while two others had not yet been filled.
The search for the missing students has so far resulted in the discovery of 19 mass graves in the vicinity of Iguala. DNA testing on remains found in the other graves is on-going.
Authorities have so far arrested 50 people, mostly local police, in connection with the Sept. 26 attack, which occurred as students from Normal Rural de Ayotzinapa attempted to leave Iguala in Guerrero state aboard three commercial buses they had earlier commandeered -- a common practice among students of the school and largely tolerated. Police blocked the buses and then opened fire. A number of students were taken away by the police and 43 were ultimately reported missing.
Family members of the 43 missing students and demonstrators have taken to the streets in Guerrero, Mexico City, Morelia, Oaxaca, San Cristobal de las Casa and Veracruz to protest organized crime and encourage the government's search for the missing. Protests turned violent Monday when protesters set fire to government buildings in Guerrero state capital, Chilpancingo, to express outrage over the alleged police involvement in the students' disappearance.
Vigilantes, like the ones who discovered the new grave sites, have joined the search for the students.