Galliani was in the vehicle when a gang of about 50 hooligans became violent, slashing his tyres and causing other damage.

"Those were 15 horrible minutes," he said. "Had the windows given way, the situation would have been more serious.

"Thankfully the police arrived."

Naples mayor Rosa Iervolino has apologised to Galliani.

"The aggression directed at the Milan club administrator is a very serious act for which as major of the city I apologise to Galliani," said Iervolino.

Napoli president Aurelio De Laurentiis also issued an apology to Galliani and said the culprits were not true Napoli fans.