Italy's culture minister hails "unprecedented discovery" in Pompeii.

An intact fresco portraying fighting gladiators has been unearthed by archaeologists in Pompei, the ancient Roman city buried under a thick carpet of volcanic ash in 79 AD.

The fresco was discovered on a wall below a staircase in what was probably a tavern frequented by gladiators, with accommodation upstairs either serving as lodgings for the owners or as a brothel.

The fresco, which depicts the end of a fight between two gladiators, is the latest find at the Regio V site to the north of the archaeological park, an area that remains closed to the public.

Italy's culture minister Dario Franceschini hailed the "unprecedented discovery by archaeologists, who for the first time since 79 AD were digging in an area never investigated until today."

The discovery was announced the same day that a major exhibition dedicated to Pompeii opened in Rome.