Twenty skeletons have been found in a hidden cemetery in Mexico near the US border

Mexico City – Mexican authorities have found 12 bodies buried in a hidden cemetery in northern Chihuahua, Mexico, officials said Thursday.

Authorities found 11 graves containing 12 bones in the municipality of Ascension near the US border, the state attorney's office said in a statement.

“This was discovered during the tracking campaigns that took place on December 18, 19 and 20,” it said.

“The remains and unidentified evidence have been transferred to the Forensic Medical Service laboratory” in the city of Ciudad Juarez to determine the possibility of determining the cause of death, the statement said.

Drug carts and gangs in Mexico they often use such secret dumping grounds to dispose of the bodies of their victims or rivals, the Associated Press said. That contributed to Mexico's biggest missing persons problem – about 120,000 at this time.

Relatives of many of the missing are left to search alone and often form volunteer teams that go out into the desert to look for hidden graves. It was not clear if any volunteer groups helped find the Ascension Cemetery.

Chihuahua has been plagued for years by violence related to organized crime such as drug trafficking and migrant smuggling to the United States.

It has recorded 3,927 missing persons since 1952, according to official figures. Jalisco and Tamaulipas, the states hit hardest by the violence, recorded more than 13,000 missing persons each during the same period.

Mexico saw over 450,000 people killed related to drugs violence since the government sent troops to fight human trafficking in 2006, according to official figures.