Violence in Mexico: 12 bodies found in clandestine graves near the border with the U.S.

At least 12 bodies were found in several clandestine graves in the northern Mexican state of Chihuahua, bordering the United States, local authorities said Thursday.

The discovery occurred in a spot in the municipality of Ascensión, located about two hours from the border town of Ciudad Juarez, where 11 graves were found and which 12 skeletons were extracted, the Chihuahua prosecutor's office said in a statement.

"The discovery was made during tracking operations that took place on December 18, 19 and 20," the agency said.

The prosecutor's office explained that during those days, government agents were located the various clandestine graves in the area by expanding the search perimeter.

"The undetermined skeletons and evidence were transferred to the laboratories of the Forensic Medical Service" in Ciudad Juarez, it added.

Chihuahua has been hit for years by violence linked toorganized crime as it is a route for the drug transit and the trafficking of migrants to the United States.

The state has 3,927 missing persons since 1952 to date, far from other states hardest hit by this phenomenon such as Jalisco in the west and Tamaulipas in the north, which have more than 13,000 cases in the same period, according to official figures.

Since December 2006, when a controversial military anti-drug operation was launched, Mexico has accumulated more than 450,000 violent deaths and tens of thousands of disappearances, according to official figures.