Police said they would continue searching for more bodies near the grave located in the outskirts of Ciudad Juarez, a city of 1.3 million people which has emerged as one of the country's most violent areas.
The most violent areas have been along the vital drug-trafficking routes near the northern border, which resulted to the death of at least 6,000 people in 2008 and around 1,000 in 2009 so far.
In a separate incident on Saturday, police announced the arrest of a man who allegedly led operations for Zetas, a group of hit men working in the eastern border city of Reynosa.
Sergio Pena Mendoza, 39, is also suspected of participating in an unsuccessful plot to free an imprisoned Zetas leader from jail in neighboring Guatemala, authorities told a news conference in Mexico City.
Felipe Calderon, the Mexican president, launched a massive assault on drug cartels in an effort to curtail the violence.
Since entering office in late 2006, Calderon has deployed more than 36,000 troops to the troubled Mexico-US borders.