The infants were buried in pairs inside funeral baskets or in ceramic urns near a 10 meter (32 feet) tall circular stone brick tower known as Chullpa Lagarto (Lizard Chullpa).

The children were buried with a volcanic stone on their chest, and are surrounded by offerings -- animals, food, dishes and pitchers. Early research suggests they were sacrificed during a period of warfare.

"The faces of the children point towards the east," where the sun rises, said Arisaca. He estimated the children were buried between 600 and 700 years years ago.

The children also had artificially elongated skulls, common among some nobles of the time.

Up to now the remains of 200 people have been unearthed around the Chullpa Lagarto, Arisaca said.

In September Arisaca announced the discovery of the 700 years-old remains of a two year-old boy at a separate funeral tower in Sillustani, buried in a ceramic urn along with a dog.

At another funeral tower nearby experts found the remains of 12 adults buried together along with food, ceramics and animals. Archeologists found sheets of gold attached to the clothing as part of the attire.

The funeral towers, are common sights in the high Andean region between Peru and Bolivia, are the burial sites of ancient nobles and community leaders.

Most are round towers built of stone, but some are rectangular.