According to officials, the attackers launched grenades and fired assault rifles at a base in the town of Karabulak in Ingushetia, a region that borders Chechnya.
Police say there were six attackers altogether and that they are still searching for the other three.
(RIA Novosti, ORT Television)
RFE/RL Caucasus Report
SUBSCRIBE For weekly news and in-depth analysis on Armenia, Azerbaijan, Georgia, and Russia's North Caucasus by e-mail, subscribe to "RFE/RL Caucasus Report."