ROME, Dec 18 (Reuters) - The highly contagious Omicron variant of the coronavirus is spreading quickly in Italy, with new cases identified in the country"s north and south, the national health institute (ISS) said on Saturday. The ISS reported that its network of regional laboratories had so far identified 84 Omicron cases, "a strong acceleration" from 55 early on Friday. Thirty-three of the cases were found in the northern region of Lombardy, around Milan, and a further 20 in the southern region of Campania, centred on Naples. ISS President Silvio Brusaferro said the spread of Omicron was "widely expected, in line with what we have seen in other countries, and we will probably see an increase in cases in coming days". Italy, the first Western country to be hit by the COVID-19 pandemic early last year, has seen new infections and deaths rising in recent weeks, but daily caseloads remain well below some other European countries such as Britain and Germany. Italy reported 120 coronavirus-related deaths on Friday against 123 the day before, while the daily tally of new infections rose to 28,632 from 26,109.