Ten skeletons precisely arranged in a bizarre spiral formation have been discovered by archaeologists investigating a 2,400 year old burial site in Mexico.

The skeletons include adults, children and even an infant. They were buried with interlinking arms in a large ring. Two have been identified as female and one as male. The ancient bones were found at an archaeological site in the town of Tlalpan, just south of Mexico city.

In a dark twist, archaeologists from Mexico's National Institute of Anthropology (INAH) and History said in a statement that because of the strange way that they were laid out, the bodies may have been part of a ritualistic burial.

However, it is not yet known whether their deaths were natural or also part of the ritual.

“There was one individual over the other, for example,”explained Jimena Rivera, director of the excavation to local news outlet Noticieros Televisa. “The head of the individual on the chest of the other, the hands of one individual under the other’s back, the baby on the body of another.”

“We believe that it could be some interpretation of life, because individuals have different ages : There is a baby, a child, an infant, some young adults, adults and an older adult.”

The researchers added that at least two of the skeletons have intentionally deformed skulls while others have deformed teeth. As well as the skeletons, there were also a number of artifacts including clay pots and round bowls.

The strange burial ground was found hidden under a building that housed a priest’s dorms and classrooms. Those buildings were erected long after the remains were buried as the bones date back 2,400 years to Mexico’s pre-classical era.