People wearing face masks at a shopping street in Osaka. Photo: AFP / Takayuki Hamai / The Yomiuri Shimbun

Tokyo reported another large jump in virus cases on Thursday, again shattering records, as the government expanded restrictions to eight more regions only days before the Olympics end.

Tokyo is already under a virus state of emergency but is seeing an exponential growth in cases, driven by the more contagious Delta variant.

On Thursday, the city reported 5,042 cases, up from 3,865 a week earlier, and 1,979 the week before that.

Daily case numbers have also broken records nationwide, topping 14,000 for the first time on Wednesday.

“Infections are spreading with a speed we have never experienced before,” Prime Minister Yoshihide Suga said at a virus taskforce meeting on Thursday.

“With the rapid increase of cases, the number of patients in serious condition, which had been contained, is growing,” he warned.

Japan’s virus outbreak has been comparatively small overall, with about 15,000 deaths and no harsh lockdown measures, but only around a third of the population is fully vaccinated.

Six parts of the country are under a virus emergency, which bans restaurants and bars from selling alcohol and asks them to close by 8pm.

Other parts of Japan are under so-called quasi-emergency measures, with the government expanding those restrictions to another eight areas on Thursday.

The measures also limit opening hours and alcohol sales, but experts have questioned whether any of the restrictions are sufficient.

“At this point in time we really need to introduce some other kind of measures in order to tackle this situation,” warned health expert Koji Wada, a professor at Japan’s International University of Health and Welfare.

The spike comes with the Olympic Games in full swing in Tokyo, taking place largely without spectators.

Organizers have reported 353 cases among Games staff, officials, teams and media since July 1.

But they insist there is no evidence of infection spreading from the Games into Japan.