MILAN (REUTERS, BLOOMBERG) - Rolex ran full-page newspaper ads in Italy saying the Italian government damaged its image by portraying the perpetrators of a violent protest as spoiled children whose parents could afford to buy them timepieces made by the luxury Swiss watchmaker.

The luxury watchmaker also demanded an apology on Wednesday from Prime Minister Matteo Renzi and Interior Minister Angelino Alfano.

In an open letter addressed to the two leaders, Mr Gianpaolo Marini, the head of the luxury watchmaker's Italian unit, said the Geneva- based company needed to "defend the brand's reputation and image." The ad appeared in at least six of Italy's biggest dailies, including Il Sore 24 Ore and Corriere della Sera.

A demonstration held in central Milan against the Expo Milano 2015 fair turned violent on Friday, with protesters torching parked cars, smashing shop windows and clashing with police who fired tear gas.

In his address to parliament on the riots - protests against Milan's Expo global fair - Mr Alfano said police photos showed that one demonstrator who defaced a bank window appeared to be wearing a Rolex. "Yesterday, on the streets I saw b******s wearing hoods and rich, spoiled brats with Rolexes," Mr Alfano told parliament.

Later, Premier Mr Renzi thanked the citizens of Milan for cleaning up the damage caused by "those with Rolexes who went around destroying shop windows".

The watchmaker, which sponsors major sporting events and has supported Milan's famous La Scala opera house, was not pleased.

The comments "produced the unacceptable association of Rolex's image with the Milan devastation," the Rolex executive said.

Rolex is the biggest Swiss watch brand.

Mr Marini said in the open letter that the low quality of the pictures of the violent demonstrators left considerable doubt as to whether they were wearing Rolexes and whether they were real or the cheap knock-offs sold on Italian streets.

Both the prime minister and the interior minister had no immediate response to the advertisement.