Japan has hit a record single-day number of Covid-19 cases in the last 24 hours, according to public broadcaster NHK said.

The country's daily virus cases have exceeded 100,000 cases, marking a fresh high, NHK reported.

Reuters reports most regions in Japan are now under infection control measures to try to blunt the spread of Omicron that has exploded among a population where less than five per cent have received vaccine booster shots.