Russian archaeologists have resumed excavations in a remote site near the Arctic Circle in the attempt to understand a perplexing find of medieval mummies clad in copper masks.

Roughly 1,000 years old, the mummies were found during a series of excavations that started in 1997 in a Siberian necropolis near the village of Zeleniy Yar, at the base of a peninsula local people called "the end of the Earth."

The archaeologists found 34 shallow graves with seven male adults, three male infants, and one female child wearing a copper mask. Buried with a hoard of artifacts, most of the bodies had shattered or missing skulls, and smashed skeletons.

Five mummies were unearthed still shrouded in copper and blankets of reindeer, beaver, wolverine or bear fur, while three copper masked infant male mummies were found bound in four or five copper hoops two inches wide.

The best preserved mummy was a red-haired man found in a wooden sarcophagus. He was covered chest to foot in copper plate and was laid to rest with an iron hatchet, furs and a bronze head buckle depicting a bear.

"Nowhere in the world are there so many mummified remains found outside the permafrost or the marshes," Natalia Fyodorova, of the Ural branch of the Russian Academy of Sciences, told the Siberian Times.

The soil at the site is sandy and not permanently frozen. Scientists have determined that the mysterious people were mummified by accident due to a dip in temperatures in the 14th century. The copper may have also prevented oxidation of the remains.

‘Frankenstein' Mummies Are a Mix of Corpses

Intriguingly, the legs of the dead all point toward the nearby Gorny Poluy River. According to Fedorova, such posture might have had a religious meaning. However, archaeologists admitted the graves feature burial rites they had never seen before.

Excavation was halted in 2002 following objections by local people who feared the archaeologists disturbed the souls of their ancestors. But work has resumed now.

"It is a unique archaeological site. We are pioneers in everything from taking away the object of sandy soil, which has not been done previously," Fyodorova said.

Photos: Mummy Stash Found in Italian Church

Among the artifacts discovered near the copper clad mummies are an iron combat knife, bracelets, silver medallions and bronze figurines.

The archaeologists also found bowls originating in Persia, some 3,700 miles to the southwest, dating from the 10th or 11th centuries.

The finding suggests that around one millennium ago Siberia was not a remote and inhospitable site, but an important trading crossroad.

Further research on the mysterious people will include genetic tests.

Image:The best preserved mummy was unearthed from a wooden sarcophagus and contained a red-haired man. Credit: Kate Baklitskaya/Siberian Times.