Fighting has erupted between a small group of Karachay Mujahiddeen and Russian occupation forces in the North Caucasus town of Cherkessk. (Karachay-Cherkessia).
Russian media said troops sealed off an apartment block in the town centre, where about three gunmen were holed up.
A Russian TV reporter said several explosions were heard and residents were evacuated from the area. Battle continuing.
Cherkessk, capital of the occupied by Russian force republic of Karachay-Cherkessia, lies west of war-ravaged Chechnya.
The besieged apartment block is on Lenin Prospect, the town's main street.
Karachay-Cherkessia has seen less militant violence in recent years than the republics immediately adjacent to Chechnya - Ingushetia and Dagestan. But Karachay-Cherkessia included into Caucasus Front on 2005 y.
Agencies