The girls' parents reported them missing Wednesday afternoon, about four hours after they failed to return home from school, ITAR-Tass reported. They were found in an apartment in the same apartment complex they live in.
Svetlana Kokotova, a regional police spokeswoman, said Anastasia Boraborkina and Olga Markelova were being examined by doctors and psychologists.
The search that began late Wednesday involved 500 police officers and dog-handlers. Vladimir Markin, a spokesman for investigators, said a murder file was opened, which he said is routine when children are reported missing.
Bryansk is in southwest Russia near the borders of Belarus and Ukraine.