Canada's First Quantum Minerals said on Monday two people died at its Zambian operations last week.
The miner said a worker from its contracting partner, Reliant Drilling, died at First Quantum's Kansanshi operations following a fall of ground due to an underground dewatering decline on Thursday.
In a separate incident on Friday, a contractor was killed in a light-vehicle accident at Sentinel mine, First Quantum added.
First Quantum has been facing massive protests since the Panama government signed a new contract for the company's Cobre Panama mine, amid allegations of corruption and lack of transparency in the negotiations.
The company has denied any wrongdoing.