A woman paints shoe prints representing the disappeared at the Teuchitlan recruiting ranch during a protest at the Jalisco government palace in Guadalajara, Jalisco state, Mexico on March 23, 2025. (Photo by Ulises Ruiz, AFP 

Two ex-police officers have been arrested in Mexico for alleged links to a suspected drug cartel training ground where bones, shoes and clothing were found earlier this month, authorities said Sunday.

The discovery of human remains at what Human Rights Watch has called an "apparent mass killing site" has caused shock in a country where murders and kidnappings are daily occurrences.

One of the former officers is accused of kidnapping a man who was held at the Izaguirre Ranch in Teuchitlan in the western state of Jalisco, the state attorney general's office said in a statement.

The former agent and colleagues detained the victim for a supposed search as he was riding a motorbike, before handing him over to a group who took him to the site, it said.

The man was later released from the ranch following an armed confrontation, the statement added.

Families searching for some of the more than 100,000 people missing in Mexico discovered bodies on March 5 at the site where forced recruits are thought to have been held.

Some 124,000 people are officially registered as missing in Mexico, mostly since 2006 when the government declared war on drug cartels.

The Guerreros Buscadores collective -- a group dedicated to locating missing people -- described the site as an "extermination center" with "clandestine crematoriums".

The Mexican attorney general's office, which is set to take over the investigation, said Sunday that a second former police officer had been arrested in connection to the case.

Both ex-officers belonged to a police force whose chief had already been detained.

Attorney General Alejandro Gertz promised Wednesday there would be no cover-up in the investigation, 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.