JOHANNESBURG, Oct 22 (Reuters) – Armed men invaded a metallurgical plant owned by South Africa’s DRDGold on Monday night, killing the gold miner’s chief security officer and stealing an estimated 17kg of gold, the company said.

DRDGOLD’s chief security officer Bart Coetzee was fatally wounded in an exchange of gunfire during the attack at the Ergo plant in Brakpan, about 45km east of Johannesburg.

The gang stole “a quantity” of calcine concentrate containing an estimated 17kg of gold, the company said in a statement on Tuesday.

“We are outraged by this callous and cowardly attack and will give our full support to the South African Police Service to ensure that these criminals, and the people they work for, are brought to justice,” DRDGold Chief Executive Niël Pretorius said.

Shares in the gold miner fell on the news, last trading down 2.7% on the Johannesburg stock exchange.

The robbery comes as mining companies across South Africa battle with increasing numbers of illegal miners.

Rising gold prices make mining an attractive prospect as high unemployment takes its toll.