Islamic insurgents killed four Russian soldiers Sunday and wounded another 16 during a clash in the mountains of southern Chechnya.
The Russian Interior Ministry says four militants were killed and two wounded in the fighting.
The military operation was hindered by deep snow and thick fog. The Russian soldiers resumed their search for the militants Monday.
Russia has been fighting Islamic insurgents since the collapse of the Soviet Union in the early 1990s.
Some information for this report was provided by AP and AFP.