New Delhi, Aug. 1 -- Utility workers excavating trenches to expand underground gas networks in Peru's capital unearthed two pre-Incan tombs on Thursday. One was empty, but the other held the 1,000-year-old remains of an individual, alongside four clay vessels and three pumpkin shell artifacts.

This isn't the first time Calidda, the company that distributes natural gas in Lima, has found archaeological remains. Over more than two decades of excavation work to expand the underground network, the company says it has made more than 2,200 discoveries.

According to archaeologist Jose Aliaga, the vessels' iconography and their black, white, and red colors "allow us to establish a connection with the pre-Incan Chancay culture,' which is approxi...