Energy company workers in Peru discovered a dozen centuries-old tombs from pre-Inca cultures during the construction of a gas pipeline, according to the project's archaeologists, in the latest find from the South American country's rich ancient past.

The oldest burials date back eight centuries and likely belong to Peru's Huaura culture, while others probably pertain to the Chancay culture from around 600 years ago, said archaeologist Cecilia Camargo.

She said that beyond the skulls and other bones found in the dry sandy soil in Peru's Carabayllo district, about 50 miles (80 km) north of Lima, some of the tombs also included pottery as well as small clay figurines, possibly representing goddesses.

The remains of both adults and children were found inside burial bundles, explained archaeologist Roberto Quispe.

Both Camargo and Quispe work for local gas distribution company Calidda, which employs its own archaeologists due the frequency of ancient discoveries whenever a project involves digging.

While best known for the picturesque mountain-top Inca royal retreat of Machu Picchu, which draws millions of tourists every year, Peru was home to various pre-Hispanic cultures that thrived in the centuries before the Inca empire rose to power, mainly along the country's central coast and in the Andes.

In the latest discovery which was made earlier this week, along with a large amount of bones, clumps of what appear to be human hair could also be seen peaking out from the dirt.

"These people were buried with very interesting offerings," added Camargo, noting that the goddess figurines may have been meant to accompany the deceased along their journey to the afterworld.