Eight miners are reportedly still missing following a flooding event at Alrosa's Mir underground, located in the remote Yakutia region of eastern Siberia.

Around 151 miners were said to be working at the site when the accident took place last week. It is believed that water flooded into the shaft of the Mir mine from an open-cast mine above it.

Rescue operations have been underway since the time of the event, and by the end of the week approximately 135 miners were reported to have been rescued.

"Rescue operations have been underway since the time of the event, and by the end of the week approximately 135 miners were reported to have been rescued."

The Mir mine is operated by the Mirninsky mining and refining facility and was originally launched in 2009 with a production capacity of one million tonnes of ore per year, according to TASS.

Output from the mine stood at 3.19 million carats of rough diamonds last year, the news agency reported.

Alrosa Group produced 37.4 million carats of rough diamonds during the same period.

The company operates in Republic of Sakha (Yakutia) and Arkhangelsk region, with 11 kimberlite pipes and 16 alluvial deposits.