Video shows charred spots on the soil suggesting some bodies may have been partially burned.

The state attorney general's office in Nuevo Leon state, where Monterrey is located, says the bodies were too badly decomposed for immediate identification.

The grave site was discovered on Thursday, and is believed to have been used by drug gangs that operate in the area.

Hit men with the Mexican Cartel have been known to use mass dumping sites to dispose of their victims.

In late May, police in the central Mexico tourist town of Taxco discovered 55 bodies in an abandoned silver mine.

And on Thursday, at least 7 people were killed in Ciudad Juarez.

Some of the bodies were dumped in a camp, with warnings scrawled across their bodies.

Overall, nearly 25-thousand people have been killed in Mexico since the government launched an offensive against drug cartels in late 2006.

AP