MOSCOW (AP) — Russian officials say they have checked over 100 medical workers who helped treat victims of a recent explosion and found one man with a trace of radiation.

The Aug. 8 incident at the Russian navy's range in Nyonoksa on the White Sea killed two servicemen and five nuclear engineers and injured six. It was followed by a brief rise in radiation levels in nearby Severodvinsk, but the authorities insisted it didn't pose any danger.

The Arkhangelsk regional administration said Friday that 110 medical workers have undergone checks that found one man with a low amount of radioactive cesium-137. It said the man's health isn't in danger and argued that he could have got the isotope with food.

The statement followed Russian media reports claiming that dozens were exposed to radiation.