Italy's state-owned railway corporation, Trenitalia, has come under attack for racism and segregation in its latest plans to replace the traditional first and second classes on its high-speed trains with four categories.

Passengers in "standard" class, the lowest of the four tiers, will be prohibited from using the on-board cafeteria and restricted from accessing other carriages.

More controversially, Trenitalia's promotional video for the changes used a black family in order to illustrate the services offered in this most basic class.

Blogger Alessandro Gilioli first drew attention to the xenophobic overtones of the advertising campaign on the website of weekly L'Espresso.

"And if the concept [of social segregation] wasn't clear enough, here is the image chose to publicise the lowest class: a coloured family, presumably immigrants. Curiously, all the clients in the Premium and Executive classes are white.

"Now, considering this is all "a marketing choice", I would love to know how much the marketing directives of Trenilatia make a month... I bet it's a salary that consents them to go to the [on-board] bar without being disturbed by negros on low incomes."

The campaign prompted a backlash on social networking sites Facebook and Twitter, where people accused Trenitalia of being "racist" and dubbed the advert "grotesque."

In response, the video has been hastily withdrawn and replaced with a version in which the occupants of standard class are depicted as a smiling white family.

"Taking action following the internet debate that has developed in recent days surrounding the photograph of the new Frecciarossa, chosen simply to publicise the new services offered and with no obvious intent to offend, Trenitalia has decided to substitute the image on its website," the company said Wednesday in a statement.

"The decision was taken in order not to fuel groundless accusations," it added.

"The subjects depicted in the images represent the diverse types of clients... that travel everyday on Trenitalia, a reflection of the new Italian society: open and multi-ethnic."