Mining giant Rio Tinto has confirmed a blast at one of its mine sites has caused damage to an ancient rock shelter.

The incident occurred last month near the Nammuldi iron ore mine in WA’s Pilbara region.

Rio Tinto says a large rock and a scrub tree fell from above the entrance to the cave following a blast.

The company says it has apologised to traditional owners who had previously warned Rio Tinto of the site’s significance.

It comes three years after the infamous Juukan Gorge destruction and just a month after WA’s cultural heritage laws were scrapped by the state government.