Napoli fans preparing to celebrate the club's first Italian league title since 1990 have been told to steer clear of Mount Vesuvius, the volcano that overlooks the southern city of Naples.

Park authorities became concerned at reports that Napoli's fanatical fans planned to set off flares to light up Vesuvius in the Italian national colours should the team clinch the title on Sunday, branding the stunt dangerous.

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Runaway leaders Napoli will secure the club's third Serie A crown if they beat visitors Salernitana and second-placed Lazio drop points against Inter Milan at San Siro.

"We are all pleased for Napoli's success which will bring honour to our region and great joy for people," said Vesuvius park commissioner Raffaele De Luca.

"But the celebrations must remain within the limits of civil behaviour," he added.

Vesuvius famously erupted in AD79 when it destroyed the nearby Roman city of Pompeii but it remains active.

Naples has been gearing itself up for a party that has been on hold for several weeks.

Normally superstitious about mentioning the word "scudetto," Neapolitans have been festooning the city with banners, flags and life-sized replicas of Napoli players.

Around 10,000 fans welcomed the team back from Turin last Sunday following a last-gasp 1-0 victory at Juventus that put Napoli on the brink of its first Serie A title in 33 years.

Thousands of motorbikes and scooters followed the team bus. The convoy was filmed by Napoli forward Victor Osimhen, who could be heard exclaiming: "It's crazy man, it's crazy, my voice is gone."

Napoli's home game against Salernitana was moved forward a day to Sunday for public safety reasons, Serie A confirmed on Friday.

Napoli were initially scheduled to play Salernitana on Saturday, with Lazio visiting Inter a day later which could have seen Napoli fans celebrating outside the stadium in Milan.

Napoli will now take on Salernitana at 3 p.m. local time on Sunday following the change, less than an hour after the score at the San Siro is known.

Information from Reuters and the Associated Press was used in this report.