Four knife-wielding prisoners claiming to be Islamic State group militants launched a deadly attack in a penal colony in southern Russia on Friday before being killed and their hostages released, officials said.

The attack left four people dead, while the four hostage-taking prisoners were “neutralized” by snipers, Russian officials said.

The attackers initially seized eight penal colony employees and four fellow inmates, according to Russia’s Federal Penitentiary Service.

“The criminals…