Detailed Instructions: In this task, you are given a text of many news articles seperated by special token "|||||". Your task is to summarize them.
Q: If the graves turn out to contain the students, it will suggest that they were summarily executed by their captors, be they police or cartel criminals. And if that proves true, it would constitute the most egregious human rights atrocity in the 2-year-old government of President Enrique Peña Nieto and one of the worst in recent years. ||||| Forensic workers arrive at the morgue in Iguala Mexico, Sunday Oct. 5, 2014. Mexican forensic experts recovered 28 charred bodies from a clandestine grave on the outskirts of this city where police engaged... (Associated Press) 
  
 IGUALA, Mexico (AP) — A clandestine grave on the outskirts of a Mexican city where police clashed with student protesters a week ago contained 28 bodies but the remains are too damaged for immediate identification, state officials said. 
  
 Guerrero State Prosecutor Inaky Blanco said he could not say whether any of the dead could be some of the 43 college students reported missing after the violent confrontation in Iguala, located about 120 miles (200 kilometers) south of Mexico City. 
  
 He said genetic testing of the remains could take two weeks to two months. 
  
 Blanco said one of the people detained in the case had told investigators that 17 students were taken to the grave site on the outskirts of the Iguala and killed there. But he stressed that investigators had not confirmed the person's story. 
  
 "As long as the identity of the cadavers has not been resolved we will continue the search" for the missing students, he said Sunday. 
  
 State police and prosecutors have been investigating the Iguala city police for misconduct during a series of violent incidents last weekend that resulted in six shooting deaths and more than two dozen people injured. Investigators said video showed police taking away an undetermined number of student protesters. 
  
 Authorities have presented charges against 29 people in the case, including 22 police officers detained soon after the violence. Three of the suspects are fugitives, including Iguala's police chief. 
  
 Blanco said they are still investigating the motive for the crime, adding that some of the police have connections to a local drug cartel. 
  
 Blanco said Saturday that some of those arrested provided key clues that led investigators to the six unmarked burial pits on an isolated hillside about a mile (2 kilometers) from the nearest road. The bodies had been put in the pits on top of branches and tree trunks, which were doused with a flammable substance such as gasoline and set on fire. 
  
 Vidulfo Rosales, a lawyer helping families of the missing students, said relatives of 37 of the young people already had provided DNA samples that will be used to determine if the recovered remains belong to any of the students. 
  
 As investigators worked at the grave site, up to 2,000 protesters blocked a main highway in the state capital of Chilpancingo demanding justice. "You took them alive, we want them returned alive," read a huge banner hung across the road linking Mexico City and Acapulco. 
  
 The mother of one of the missing youths said her son, 17-year-old Luis Angel Abarca Carrillo, had enrolled in the Aytozinapa teachers college attended by the missing students in order to get ahead in life and not be a poor farmer like his brothers. 
  
 "But now look what they did to him, he hasn't reappeared," said 60-year-old Margarita Carrillo. 
  
 Mexico's National Human Rights Commission opened its own investigation into the case for possible "serious human rights abuses," such as extrajudicial executions and forced disappearances by Iguala city police. 
  
 The commission said in a statement Sunday that it had warned about the "delicate" situation in Guerrero, a southern state where poverty feeds social unrest and drug gangs clash over territory. 
  
 Anger over the discovery of the graves exploded Saturday night when a group of young people from the Aytozinapa teachers college protested outside the governor's residence in Chilpancingo. They threw Molotov cocktails and overturned a car after state officials told them they would not be allowed to travel to the graves to determine if the bodies are those of their missing classmates. 
  
 Like many other schools in Mexico's "rural teachers college" system, Aytozinapa is known for militant and radical protests. 
  
 ___ 
  
 Associated Press writer Maria Verza in Mexico City contributed to this report. ||||| Image copyright AFP Image caption Mexican troops have been guarding the location where the bodies were found 
  
 Investigators in Mexico are working to identify 28 bodies retrieved from a grave near the southern town of Iguala. 
  
 The grave is located in an area where 43 protesting students went missing after clashing with police last month. 
  
 Inaky Blanco, the chief prosecutor of Guerrero state, said identification could take two weeks. 
  
 The students disappeared after taking part in a protest over teachers' rights. Police opened fire on their buses, killing six people. 
  
 Witnesses said that most of the survivors - all trainee teachers - were bundled into police vans. 
  
 Some had gone into hiding and contacted their relatives after several days, still fearing for their lives. 
  
 Twenty-two police officers are being held in connection with the 27 September shooting. 
  
 Mr Blanco said one of those detained had admitted that 17 students had been shot dead at the site where the bodies were found. But he stressed that investigators had not confirmed the suspect's story. 
  
 'Anonymous tip' 
  
 The students had been taking part in a protest over job discrimination against rural teachers. 
  
 Image copyright AFP Image caption Mexican students have been blocking roads, demanding a thorough investigation into the disappearance of their peers 
  
 Image copyright AFP Image caption The government has offered a reward of $75,000 (£47,000) for information leading to the students' location 
  
 Iguala lies about 120 miles (200km) south of the capital Mexico City. The grave was discovered on Saturday, following an anonymous tip, local media reported. 
  
 State prosecutors said local officials and police officers could have links with criminal gangs operating in Guerrero state. 
  
 Arrest warrants have been issued for the mayor of Iguala, Jose Luis Albarca, and his security chief who are both considered fugitives from justice and may be involved in the violence. 
  
 Mexico correspondent Will Grant says the incident has highlighted the extent of the collusion between criminal groups and officials in much of the country. |||||
A:
Investigators are still trying to identify 28 "savagely slaughtered" bodies found in mass graves outside the Mexican city of Iguala—but they fear they have found evidence of an atrocity carried out by local police with ties to organized crime. Six students were killed when a group of students clashed with police in the city in Guerrero state late last month, and DNA tests will be carried out on the badly burned bodies that have been recovered to discover whether they are among the 43 students, mostly men in their early 20s, who went missing after the incident, reports the Los Angeles Times. The state's chief prosecutor says it could take up to two weeks to identify the bodies found in the graves, which were found after an anonymous tip. Some 22 local police officers are among more than 30 people who have been arrested over the incident, and the city's mayor and police chief are now fugitives, the BBC reports. The teachers' college the students attended is known for militant protests, and the discovery of the graves sparked a huge protest in the state capital from parents and around 2,000 supporters, who put a huge banner saying, "You took them alive, we want them returned alive" over the highway linking Mexico City and Acapulco, reports the AP.