A Vietnamese woman was also killed in the accident, which occurred about 50 kilometers from the tourist city of Dalat as the busload of tourists returned from a day trip.
"Around 7 p.m. local time [on Friday, 12:00 GMT] the bus with Russian tourists, which was returning from a one-day excursion, fell down a precipice 50-60 kilometers from Dalat," the spokesman for the Russian Embassy in Vietnam said.
"Fourteen people are injured. The victims are being taken to a hospital," Alexei Shevtsov said.
The Vietnamese driver of the bus is among the injured. The cause of the accident is being investigated.
Similar tragedies involving Russian tour groups occurred last December in Israel and Egypt. On December 16, 2008, 24 Russians died in a bus crash near the Israeli Red Sea resort city of Eilat and six days later another seven Russians died near Dahab on Egypt's Sinai Peninsula.