Rome: Russian Ambassador in Rome Sergey Razov expressed a protest over the "unmotivated" decision of the Italian authorities to expel Russian diplomats, saying that it leads to a further deterioration of bilateral relations, the Russian Embassy in Rome said on Tuesday.

Earlier in the day, the Italian foreign ministry has summoned the Russian ambassador to announce the expulsion of 30 Russian diplomats, declaring them personae non gratae.

"The Russian Ambassador expressed a protest in connection with the unmotivated decision of the Italian side, leading to a further deterioration of bilateral relations. He stated that this step would not go unanswered by the Russian side," the diplomatic mission said, adding that there was no evidence that these diplomats' actions somehow threatened Italy's security.

The 30 Russian diplomats must leave Italy with their families within 72 hours, the embassy added.