"Unidentified assailants opened fire on a group of federal soldiers in the Kurchaloyevo District of Chechnya at about 8.15 p.m. local time (5.15 p.m. GMT), killing two contract soldiers and wounding one," the source said.
Soldiers returned fire, but the suspected militants managed to escape.
Meanwhile, federal troops and police continued on Monday the pursuit of at least 20 militants in the neighboring Vedeno District of Chechnya.
The militant group was initially spotted on Sunday by federal troops near the village of Benoy. No casualties were reported in the ensuing exchange of fire.
Chechnya suffered two devastating separatist wars in the 1990s-early 2000s. Thousands were killed and many more made homeless as federal troops attempted to regain control over the mountainous republic.
Although the active phase of the war is over, sporadic clashes with militants and terrorist attacks are common in the troubled republic, as well as in adjacent republics such as Ingushetia and Daghestan.