An explosion at an electrical transformer rattled the foothills west of Denver early Tuesday near an old uranium mine, authorities said.

Jefferson County sheriff's deputies confirmed the explosion was in a transformer on a private road near the inactive mine, spokesman Jim Shires said.

There were no injuries and no reports of radiation, he said.

The department had received a report of a possible explosion in the area of the mine around 6:30 a.m. Flames could be seen coming from what appeared to be an electrical transformer, about 15 miles west of Denver.