While bloody death tolls and ubiquitous violence are nothing new in a country that has seen an estimated 106,000 people killed in drug violence since 2006, the disappearance of 43 college students has shaken the country and spurred widespread protests across Mexico.
Human rights experts say that they have run into serious obstacles in their investigation into the case of 43 college students who went missing after being detained by police in southern Mexico in 2014.
International experts for the Inter-American Human Rights Commission said Sunday at a news conference that they were concerned about being given limited access to new information uncovered by government investigators and they criticized leaks of statements from some of those arrested in the case that the panel said "don't correspond to the truth."
They also said authorities had not allowed them be present for statements by military personnel who were witnesses of the disappearance or been given access to videos that could clarify what happened that night.
Later Sunday, the federal Attorney General's Office issued a statement reaffirming its willingness to work with the expert panel and saying it already is investigating the leaks. It denied that officials have fragmented findings from the government's investigation, which it said remains open.
In their first report in September, the expert panel rejected the official version of the government that after being killed, the students' bodies were incinerated at a dump. The panel charged at that time that some Mexican authorities had obstructed justice in the case.
The students from a local teachers college have not been seen since Sept. 26, 2014, when they were detained after clashing with municipal police in the city of Iguala in Guerrero state. Six other people were killed during the clashes, including some not involved in the confrontation.
Government prosecutors have said the police turned the students over to a local drug gang, which killed them and burned their bodies.
Based on reporting by The Associated Press.