MEXICO CITY -- Mexico needs to appoint a special prosecutor to handle the case of 43 missing college students, whose fate remains a mystery a year after they disappeared at the hands of local police and a drug gang, the Inter-American Commission on Human Rights said Friday.

Calling the situation in the country a "serious human rights crisis," Commission President Rose-Marie Belle Antoine said Mexico must implement all recommendations of the commission's independent team of experts appointed to review the investigation into the 43, who have been missing since Sept. 26, 2014, from the city of Iguala in the southern state of Guerrero.

The recommendations include replacing the investigative team and following the experts' hypothesis that the students may have disappeared while hijacking a bus carrying heroin or drug money.

The experts last month took apart the Attorney General's version that the students were mistaken for rival gang members and burned in a garbage dump.

The commission "has been able to confirm on the ground the serious human rights crisis Mexico is experiencing, which is characterized by a situation of extreme insecurity and violence," Antoine said in a press conference at the end of a five-day visit to six locations around the country.

Roberto Campa, the government's undersecretary for human rights, later denied that the country is experiencing a widespread crisis, and said that the overall situation in Mexico isn't something that can be determined in just a five-day visit.

"Certainly there are some specific cases they have presented that have worrisome conditions, but they don't reflect the situation in general for the country," Campa said in a press conference responding to the commission. He said the case of the missing 43 was not the norm, rather "an absolutely extraordinary situation."

The commission issued preliminary findings of its visit and said a full report on the human rights situation in Mexico will be issued in early 2016.

Among other things, it said Mexico has a "deeply troubling phenomenon" of extra-judicial killings by government forces, and urged the country to investigate the possibility of such killings by Federal Police earlier this year in Apatzingan and Tanhuato, both in the western state of Michoacan, where the government is battling a fierce drug cartel known as the Jalisco New Generation.

In Tanhuato, 42 suspected criminals died in an alleged shootout and only one federal police officer. In Apatzingan, nine civilians were shot dead in the street, some huddled together beneath an SUV for protection. Witnesses said they were unarmed when they met the federal police, who said they died in friendly from their same band of criminals.

The Mexican government has vehemently denied that there were extra-judicial killings in both cases, saying police came under fire and casualties came in a shootout. Though it has not done a separate probe, the commission said there were irregularities in the government's investigation and that the crime scenes had been altered to support the official claims of a confrontation.

The commission was repeatedly asked about the lack of confidence Mexicans have in the judicial system and the attorney general, and whether the country needs an independent international commission to fight impunity like that in Guatemala, where the president and vice-president have both resigned and been jailed in a widespread public corruption scandal.

Antoine said that option has not been discussed so far for Mexico. She noted in an interview with The Associated Press that there are reforms in the works for Mexico's justice systems and new laws regarding torture, victims' compensation and more expected for forced disappearances by the state.

"Our purpose is not to create substitute for the government," she said. "We have to allow the state to correct itself."

Lucia de Los Angeles Diaz, who attended the conference, saw her 29-year-old son kidnapped two years ago from the port city of Veracruz and has heard nothing since.

"It's a never-ending story, we walk from one office to the other, and every day we walk out empty handed, that's the story of our lives," she told the commission.