A strike at Freeport-McMoRan Copper & Gold’s Tenke Fungurume copper and cobalt mine in the Democratic Republic of Congo has not affected production, according to the company.

Company spokesman Bill Collier told Reuters that workers staged an illegal work stoppage at the mine starting Friday but many had returned to work after being urged by government labour officials.

“The stoppage has been non-violent and there has been no damage to equipment or property,” Collier said.

“Other departments continue to report substantial levels of absenteeism.

“Production of copper and cobalt from the mine and process plant continues on a daily basis.”

Tenke Fungurume is in the ramp-up stage, producing about 250 million pounds of copper and 18 million pounds of cobalt annually.

Touted as one of the richest copper deposits in the world, Tenke is expected eventually to produce up to one billion pounds of the metal annually.

Freeport has a 57.75% stake in the Tenke mine, while Lundin Mining holds 24.75% and the rest is owned by state miner Gecamines.