A mining company has admitted to blowing up part of an ancient Aboriginal rock cave sites tens for thousands of years old.

Aboriginal heritage sites of major significance were destroyed in WA’s Pilbara over the weekend, media there reported.

Global mining giant Rio Tinto said they had obtained legal permission to blast the sites before, the ancient sites’ full riches were uncovered.

The sites in the area had been occupied by Indigenous people for at least 46,000 years.

Local Indigenous corporation that overseas the land, PKKP, said they were “deeply troubled and saddened” by the loss of ancient sites.

“Our people are deeply troubled and saddened … grieving the loss of connection to our ancestors as well as our land,” said Puutu Kunti Kurrama land committee chairman John Ashburton.

“Losing these rock shelters is a devastating blow.”

The organisation said it had pleaded with Rio Tinto to prevent the mining activity however the blasts went ahead anyway.

A Rio Tinto spokesperson said blasting in the Juukan Gorge occurred over the weekend, and on Tuesday the company confirmed that the ancient rock shelters were destroyed.

“Rio Tinto has worked constructively together with the PKKP people on a range of heritage matters and has, where practicable, modified its operations to avoid heritage impacts and to protect places of cultural significance,” Rio Tinto said.

“In 2013, Ministerial consent was granted to allow Rio Tinto to conduct activity at the Brockman 4 mine that would impact Juukan 1 and Juukan 2 rock shelters,” the spokesperson said.

Nine Publishing reported Archaeologist Michael Slack had previously found grinding and pounding stones at the site.

The findings, to be published in the near future, include the discovery of a 28,000-year-old tool made from bone, each one of the oldest examples of these technologies known in Australia; and a piece of a 4000-year-old plaited hair belt.

What we found were some really important discoveries,” Slack said.

“We found early backed artefacts which were a little stone tool we think were halved into knives, and they appear in this site up to 10,000 years earlier than in other sites.

“This site was something special. It was a massive cave, it had such a rich cultural deposit, such an old occupation. And so significant in that respect that it’s one of those sites you only excavate once or twice in your career.