More than 140 youngsters were buried alongside three adults and 200 animals – either llamas or alpacas – from the 15th century ritual in Peru.
Scientists released images of the excavation, which began in 2011, of dead girls and boys aged five to 14 seemingly huddled together in burial pits.
Evidence links the sacrifice to a ‘climactic event’ Pic: PLOS
They were killed by having their chests cut open, many with their hearts removed.
Evidence suggests the sacrifice was to do with a “climactic event” that could have hit the “economic, political and ideological stability of one of the most powerful states in the New World”.
The human remains started to be dug up six years ago, after residents near the Huanchaquito-Las Llamas site noticed bones eroding out of the roadside.
An emergency excavation was ordered and archaeologists discovered the bodies over multiple digs of the 700 square metre site.
The number of dead could be higher, as some “incomplete remains” have been found in areas re-inhabited by humans.
Early research suggests the children were wrapped in cotton, some with their faces painted red and still with cloth around their heads when the graves were found.
The remains were first noticed by residents in 2011
They were buried facing the sea, around 350m away, while the animals were positioned facing the mountains.
Writing in the PLOS ONE journal, scientists said the sacrifice happened “shortly after a heavy rain and flood event” that swamped the area with mud, clay and gravel.
The burial site is 700 square metres
Under normal conditions, the area receives “negligible rainfall”, they added, calling it a mass sacrifice “on a scale unlike any seen previously” in the region.
The find dwarfs the discovery of 42 children killed in a mass sacrifice at the Mexica Templo Mayor in central Mexico.
