The incident occurred in the Olyutor Range, in Kamchatka's Koryak Autonomous Area.
"According to preliminary information, both victims were specialists based with a geological field party working for [local mining company] KoryakGeolDobycha," the spokesman said
A team of police officers has flown to the scene in a helicopter.
The Kamchatka brown bear is one of the world's largest bear species, weighing around 700 kg (1,500 pounds), and with body length of 3 meters (10 feet).
Around 16,000 bears currently inhabit the region, and on average kill three people per year. According to Russia's agricultural regulator Rosselkhoznadzor, the local bear population is on the rise.