Police said they were trying to find a network of accomplices they suspect helped 'ndrangheta clan bosses Giuseppe Crea and Giuseppe Ferraro elude capture for 10 years and 18 years respectively. Crea, 37, faces 22 years in prison for Mafia association; Ferraro, 48, was sentenced to life imprisonment, including for a murder conviction.
The two had a dozen firearms, including a Kalashnikov, neatly hung up on a wall, video released by police of the bunker's interior showed.
Despite being dug deep into the ground, the hideout was furnished with electricity, satellite TV and a computer, police said. Vines and bushes camouflaged the hideout in the province of Reggio Calabria.
Ferraro is considered one of the last survivors of a decades-long ferocious 'ndrangheta clan feud that claimed at least 20 lives, according to police.
Announcing the capture of the pair, Italian Interior Minister Angelino Alfano noted they were "both on Italy's list of most dangerous fugitives".
Authorities described the two as clan bosses from 'ndrangheta territory near Gioia Tauro, a port on the Tyrrhenian coast which investigators have long maintained the syndicate uses as a base for activities such as drug and arms trafficking.