A border guard gunned down seven servicemen and injured six others at a checkpoint in Dagestan before being shot dead himself, investigators said Wednesday.
Sergeant Ramzan Aliyev approached a border post in the city of Derbent about 4 p.m. Tuesday and fired at least 30 rounds from his AK-42 "for no apparent reason," killing two border guards and wounding two others, the Investigative Committee said in a statement.
Aliyev next walked over to a group of Altai police officers visiting Dagestan on a service trip, shooting dead five of them and wounding four others. Armed servicemen then returned fire, killing Aliyev.
Earlier reports said eight people died.
Interfax, citing an unidentified law enforcement official, speculated that Aliyev might have been an Islamist militant. The official said Aliyev's superiors had tried to dismiss him three times for reading fundamentalist Muslim literature.