A $2.2-billion mining tunnel in South Africa has started to produce its first diamonds, mining giant De Beers said on Tuesday.
In 2012, the global firm started digging beneath the country's largest diamond mine, Venetia, seeking to reach gems at a depth of more than 1,000 metres (3,250 feet).
Venetia is an open mine in northeastern South Africa, close to the border with Zimbabwe and Botswana, that closed in December 2022 after 30 years of production.
The firm described the first diamonds as "a key milestone" but did not give further details.
The underground operation, employing about 4,300 people, is now 70 percent complete, it said.
The facility is expected to produce between 4.5 million and 5.5 million carats of diamonds annually.
De Beers managed operations' director Moses Madondo said the investment enhanced the group's "production for the long term" and was an indication of its commitment to South Africa.
"We look forward to seeing this high performing team continue the good work as we ramp up production over the next few years," he said.