The criminals broke into a house in the town of Karabulak at around 1:00 a.m. and shot Vera Draganchuk's husband and two sons, 20 and 24 respectively, with an automatic rifle.
"The woman was hiding and the murderers could not find her," the source said adding that Vera also had a daughter but that her fate was unknown.
This is the latest crime in a series of similar incidents in the republic neighboring troubled Chechnya, which saw two Moscow-led military campaigns against separatist regimes in the 1990s- early 2000s.
In the early hours of July 16, ethnic Russian teacher Lyudmila Terekhina, 55, and her son and daughter were shot in their house in the town of Ordzhonikidzevskaya. Policemen said possible motives were robbery and nationalistic sentiments. At their funeral two days later a tripwire bomb went off leaving 11 people injured.
The region is inhabited by a predominantly non-Slavic Muslim population.
