A Russian soldier shot four colleagues dead Monday at their base in Chechnya, before being gunned down, the National Guard they were members of said in a statement.
The soldier, a lieutenant, opened fire at around 4:00 pm (1300 GMT) in a barracks near the village of Shelkovskaya in the mainly-Muslim Chechnya region in southern Russia, the Interfax news agency cited the National Guard as saying.
The National Guard said a panel would be set to investigate the shootings.
The slayings come less than a month after a Russian soldier fatally shot three other servicemen during drills and wounded two others. He was tracked down and killed.
President Vladimir Putin created the National Guard security force last year, a move analysts said could be aimed at warding off unrest over the country's economic crisis.
The National Guard answers directly to Putin and is tasked with tackling terrorism and organized crime as well as maintaining order.
But armed attacks on authorities and forces are frequent in the Russian Caucasus.
In early October, the Daesh terror group claimed responsibility for an attack that left two policemen dead in Dagestan, the volatile region neighboring Chechnya.
Russia has also received numerous threats of reprisals from Daesh and Al-Qaeda since its military intervention in Syria in 2015.