Researchers at the Sillustani archaeological site in Peru say they have found the bodies of 44 children thought to have been sacrificed between 600 and 700 years ago.
They were buried in pairs in baskets placed around stone funerary towers.
Researchers said their ages ranged from newborns to three years old.
The archaeologists believe they belonged to the Kolla culture, which ruled parts of the Puno region of southern Peru between 1200 and 1450.
All the bodies had a volcanic stone placed on their chest, and were surrounded by a variety of offerings, including animals, food, dishes and pitchers, archaeologist Eduardo Arisaca said.
Researchers at the site say ceramics with paintings of scenes of war found with the bodies suggest the children were sacrificed during a period of conflict between the Kolla and a rival culture.
They said the bodies were found near a 10m-tall (32ft) circular stone tower known as Chullpa Lagarto.
The bodies of some 200 people have been unearthed near the tower at the Sillustani site some 1,300km (800 miles) south-east of the capital, Lima.