The soldiers were killed in two separate attacks on Saturday, one inside Grozny and one in the village of Starye Atagi south of the capital, reports said on Sunday.
In Grozny, two soldiers were killed and one injured when separatist fighters opened fire on them in the Staropromyslovsky district, Chechnya's interior ministry told Interfax.
In Starye Atagi, a group of 15 fighters killed three soldiers and injured six after opening fire on their living quarters, the interior ministry told RIA Novosti.
Two of the fighters were killed by return fire in the attack, it said.
Separatist fighters in Chechnya usually increase their attacks on pro-Moscow targets in the mountainous republic in spring and summer.
Chechen separatists have been fighting Russian forces on and off for much of the past decade. The separatists won the first Russo-Chechen war of 1994-1996, with the republic gaining de facto independence.
The Kremlin re-deployed its forces in October 1999 in what it called a lightning-strike, "anti-terrorist" operation.
Heavy combat ended within a year, but a war has simmered since then, claiming civilian, troop and separatist lives on an almost daily basis.