The Ouray County coroner's office confirmed the fatalities at the Revenue-Virginius Mine in Ouray County, the Ouray Watch reported.
The identities of the two dead miners, whose bodies remained underground Sunday afternoon, had not been released, the newspaper said.
The injured miners were taken to hospitals in the region. One was reported in critical condition.
Rory Williams, project manager for Star Mining Operations,which operates the Revenue-Virginius mine, said the miners were victims of "a powder-smoke incident" and the release of chemicals, the Watch said.
U.S. Mine Safety and Health Administration staff were at the mine site.