WASHINGTON (Reuters) -Italy's government said on Wednesday that seven mobile phone users in the country had been targeted by spyware on Meta Platforms' WhatsApp messaging service, and it called the incident "particularly serious".

Prime Minister Giorgia Meloni's office said it asked the National Cybersecurity Agency to look into the affair, while denying any involvement, after reports that a journalist and a well-known migrant rescue activist had been targeted.

Luca Casarini, co-founder of the Mediterranea Saving Humans charity, showed Reuters the spyware alert he had received from WhatsApp on Friday. It was the same day Meta publicly accused surveillance company Paragon Solutions of targeting roughly 90 users in more than two dozen countries, including an unspecified number of reporters and activists.

In a statement, Meloni's office said the cybersecurity agency was informed by WhatsApp, via a law firm, about seven confirmed cases in Italy, but was not told the names of the people affected, "to protect their privacy."

ACN was also told that spyware was found among WhatsApp users in other European Union nations, namely Belgium, Greece, Latvia, Lithuania, Austria, Cyprus, Czech Republic, Denmark, Germany, Netherlands, Portugal, Spain and Sweden.

Meta's announcement, which was paired with a cease-and-desist letter to Paragon, alleged that the reportedly American-owned company had tried to steal data from its users using a sophisticated technique that required no interaction from its target, known as a "zero click" hack.

Meta declined to comment on the message sent to Casarini. Paragon and its owner, Florida investment group AE Industrial Partners, did not immediately respond to emails.

Casarini is often criticized by anti-migrant, pro-government newspapers in Italy for his charity's work saving migrants in the Mediterranean, where Africans desperate to reach European shores in overcrowded boats often capsize.

Casarini has previously been prosecuted for allegedly abetting illegal immigration, and he told Reuters that his communications had been intercepted as part of that case. But he said he did not know who was behind the attempt to break into his phone flagged by WhatsApp or whether it was judicially sanctioned.

"It's a violation of democracy," he said.

Casarini's disclosure came a few days after Italian journalist Francesco Cancellato outed himself as the recipient of one of the WhatsApp alerts on Friday.

Cancellato told Reuters that his online newspaper Fanpage specialized in undercover investigations, notably a recent expose of Meloni's youth wing which showed members describing themselves as fascists and shouting the Nazi slogan, "Sieg Heil."

Cancellato said he was shocked by the intrusion but wanted to reserve judgment about who was behind the hacking until his newspaper had conducted its own investigation.