Responding to the discovery of a mass grave thought to contain the bodies of dozens of students who were attacked by local police last month, Mexican federal agents on Monday were dispatched to the city of Iguala in southern Guerrero state to investigate the scene.On September 26, two busloads of students from a local teachers college, the Raúl Isidro Burgos Ayotzinapa Normal School, were attacked. According to surviving students who were interviewed by VICE News, local Iguala police and other armed men \u0022surrounded and confronted the buses on the outskirts of Iguala,\u0022 and opened fire.After the gunfire, six students were dead and dozens of the survivors fled the scene or were detained; forty-three have been declared missing. On October 5, authorities said they had discovered mass graves containing the burned remnants of \u0022at least\u0022 28 bodies thought to be the missing students. However, proper identification through genetic testing could take up to two months, say officials.President Enrique Peña Nieto called the deaths \u0022outrageous, painful and unacceptable\u0022 and said that he had ordered a newly created preventative unit of the federal security forces to take over security in the city, \u0022find out what happened and apply the full extent of the law to those responsible.\u0022Charged with keeping \u0022law and order\u0022 in the city of 140,000, the paramilitary-like forces and convoys of Army trucks are now patrolling the streets of Iguala, while federal soldiers man checkpoints.According to the Associated Press, \u0022The Guerrero state prosecutor Iñaky Blanco said there was no known motive for the attack, but officials have alleged that local police were in league with a gang called the Guerreros Unidos.\u0022 Twenty-two officers from the Iguala force have reportedly been detained.Though the Mexican government has tried to distance itself from the killings and alleged police corruption by laying the blame on Guerrero governor Ángel Aguirre, in an interview following the disappearances, human rights activist Father Alejandro Solalinde charged that the events in Iguala were not isolated events, and that Mexico was an \u0022assassin state\u0022 that has become repressive and persecuted rights activists, youth and journalists, \u0026nbsp;driving civil society to a breaking point.The students, known widely as \u0022normalistas,\u0022 had reportedly traveled to Iguala to protest an event featuring the Iguala mayor\u0026#039;s wife, María de los Ángeles Piñeda, and solicit donations for supplies for their school. According to VICE News reporter Melissa del Pozo, the school is a \u0022Revolutionary-era rural teachers college known nationally for the\u0026nbsp;ardently leftist politics that guide everything the students do and study.\u0022The Iguala police force reportedly has a history of clashes with the leftist school. \u0022The Ayotzinapa school has long been an ally of community police in the nearby town of Tixtla,\u0022 Manuel Martinez, a spokesman for the students’ families, told AP. Martinez said that along with the teachers’ union and the students, the school \u0022had formed a broad front to expel cartel extortionists from the area last year.\u0022Caught in the cross-fire of the September attack was another bus mostly containing members of a soccer club from the capital city of Chilpancingo, which was traveling in a nearby area. According to reports, around the same time as the student attack, police or armed men also opened fire on that bus \u0022apparently mistaking it for one carrying normalistas,\u0022 killing three people.Many of the relatives of those missing have descended on the Ayotzinapa school, which, in response to the murders and disappearances, has become a \u0022hub of planning and organizing for protests as students and relatives have taken to blocking major highways and protesting in Chilpancingo,\u0022 del Pozo reports.On Wednesday, normal schools across Mexico are planning to hold a national strike.