For families in Mexico searching for missing loved ones, the grim discovery of what is being called an "extermination" site with human remains and ovens, could be their worst fears some true. 

Mexican authorities are now investigating the site in the western state of Jalisco, first found last week by a group of volunteers that was believed, by the volunteers, to have been used by one of the area's cartels known as the New Generation Jalisco Cartel. 

Inside its iron gates were an increasing number of horrors, including cremation ovens, bone fragments, hundreds of pairs of shoes, clothing and even children’s toys. 

TRUMP ADMINISTRATION PROMISES TO BE ‘RUTHLESSLY AGGRESSIVE’ IN RESPONSE TO SUSPECTED CARTEL KILLING OF US CITIZEN

"They'd see the shoes and say: 'those look like the ones my missing relative was wearing when they disappeared,’" Luz Toscano, one of the volunteers, told BBC News. 

The ranch, near the village of Teuchitlán, was raided last September by Mexican authorities who failed to find or reveal the discovery of human remains. 

At the time of the raid, 10 arrests were made, two hostages were released, and a body was found wrapped in plastic. 

After authorities began searching this week, they said they also found almost 100 shell casings. 

MEXICO EXTRADITES DOZENS OF CARTEL LEADERS AND MEMBERS TO US, INCLUDING DRUG LORD RAFAEL CARO QUINTERO 

None of the remains have been identified, and the number is not yet known, but the number of personal items left behind is around 700. 

"The number of the victims that presumably could have been buried there is enormous," Eduardo Guerrero, a security analyst in Mexico City, told The New York Times. "And it resurfaced the nightmarish reminder that Mexico is plagued with mass graves."

The discovery, based on an anonymous tip, has dominated the headlines, shocking a country that has become inured by mass graves and promoted citizens to call on authorities to crack down on cartel violence. 

There are 120,000 "forcibly disappeared" people in Mexico. 

Jalisco state Gov. Pablo Lemus told critics in a video message this week that his office is fully cooperating with federal investigators and no one is "washing their hands" of the case, according to BBC News. 

CLICK HERE TO GET THE FOX NEWS APP

The ranch in Teuchitlan, about 37 miles (60 kilometers) west of Guadalajara was allegedly being used as a training base for cartel recruits when National Guard troops found it last September.

The Associated Press contributed to this report.