TEUCHITLAN, Mexico (AFP) — Desperate relatives of missing Mexicans on Thursday visited a suspected drug cartel training ground where bones, shoes and clothing were found earlier this month, seeking answers about their fate.

The discovery of human remains at what the New York-based advocacy group Human Rights Watch has called an “apparent mass killing site” has caused shock in a country where murders and kidnappings are daily occurrences.

In the hope of finding some trace of the missing, relatives examined various objects found at the Izaguirre Ranch in Teuchitlan in the western state of Jalisco where forced recruits are thought to have been taken.

“This is agony, because we’re dead inside. All I want is to know about my son. I’m not looking for culprits,” said Alejandra Cruz, whose teenage son has been missing for almost four years.

Mexico’s Attorney General Alejandro Gertz promised Wednesday there would be no cover-up, saying extensive evidence meant that the “truth will come out.”

He listed multiple flaws in the initial investigation overseen by the Jalisco state prosecutor’s office, including a failure to thoroughly search the site.

The relatives’ visit coincided with a tour of the ranch by journalists invited by authorities.

The property was searched last September after the military raided it following reports of gunfire.

According to the Jalisco state prosecutor’s office, 10 people were arrested, two captives freed and a dead body found along with skeletal remains at the time.

This month, a group of families looking for missing persons discovered more buried bones, dozens of shoes, clothing and other objects that apparently went unnoticed during the initial search.

The United Nations Human Rights Office last week called for “thorough, independent, impartial and transparent investigations” into the apparent crimes.

It said it was “disturbing” that crucial evidence was missed during the initial searches.

More than 124,000 people have been officially registered as missing in Mexico, mostly since 2006 when the government declared war on drug cartels.

Around 480,000 people have been murdered.

Mexico has a long history of human rights violations that remain unpunished, including the disappearance of 43 students from a teacher training college in 2014, allegedly at the hands of drug traffickers and corrupt authorities.