MILAN -- Italy has confirmed nine cases of the Zika virus in the country, of which four registered in northern Veneto region, local media reported on Friday.

All concerned patients have been successfully treated in Italian health facilities and all of them had returned from trips to South America or the Caribbean, where the virus is most widespread, local health authorities said.

The freshest cases of contagion were found in two people back from Brazil and the Dominican Republic, who were respectively treated in Rome and in Venice, ANSA news agency reported on Friday.

Another three cases had been reported in the past days in Treviso, Padua and Vicenza, three cities close to Venice, the capital of Veneto region.

Veneto region health councilor Luca Coletto, however, stressed that the situation was completely under control and there was no reason for an alarm, according to Venice-based Il Gazzettino newspaper.

Coletto said the regional health system has been monitoring since 2010 the possible presence of the virus there, both in Aedes mosquitoes that are its carriers, and in humans.

The virus is not deadly in general, but is very dangerous for babies born to women infected during pregnancy.

Zika has been linked to microcephaly, when babies are born with abnormally smaller heads, which can cause brain damage and even be deadly.

Health authorities in Italy have suspended blood donations from people who have travelled in affected countries and have advised pregnant women and also people with immune system illnesses or serious chronic pathologies to avoid going to the areas at risk.

Earlier this week, the World Health Organization (WHO) declared Zika an international public health emergency, after warning that the virus was spreading "explosively" and could affect between three million and four million people.

Outside Latin America, where Brazil was the country most affected by the epidemic with thousands of new cases of microcephaly registered in the past weeks, the Zika virus has been reported in several European countries.

Italian experts have said there is not a concrete risk of an outbreak of the disease in Europe, but have recommended that all citizens must step up surveillance to contain the threat.