Australia has suffered its worst day of coronavirus infections with Victoria state recording 723 new cases, dashing hopes that a lockdown in the city of Melbourne was bringing the outbreak under control.

Victoria Premier Daniel Andrews told reporters that 13 more people had died, bringing the state’s death toll to 105. Infections had gradually decreased earlier this week, with the state recording 295 new cases on Wednesday, raising hopes the six-week lockdown of the city of 5 million people was working.

“Most of today’s cases are in metro areas,” Andrews said in a statement. “But we have seen a significant jump in regional communities. It’s vital we stop this virus further seeping into regional Victoria.”

He said mask-wearing would be mandatory across the state, extending the order from just Melbourne. Residents in several regional centers, including Geelong, would not be allowed to have visitors in their homes from midnight.

There are mounting concerns that the stay-at-home order in Melbourne, begun three weeks ago, will need to be extended, inflicting further damage on the economy. Health authorities are also concerned the virus is spreading to other states and territories, most of which have gone weeks without recording community transmissions.

The Australian dollar fell 0.2% to 71.72 US cents as investors sold the currency on the spike in cases.

New South Wales state on Thursday reported 18 new cases in the past 24 hours.

Queensland, which has closed its border to Victoria and the Greater Sydney area, is ramping up testing after two women who visited Melbourne didn’t self-isolate on their return and instead went to schools, restaurants and shopping centers for eight days unchecked before returning a positive result.

The resurgence in Victoria is taking a heavy toll on residents of age-care homes and is placing the health-care system under stress. The state said Tuesday it will suspend all but the most urgent elective surgeries in Melbourne as it seeks to free up hospital beds and nurses to fight a spike of cases in such facilities.