SYDNEY, July 15 (Reuters) - Australian authorities reported a slowdown in new COVID-19 cases in Sydney on Thursday, as the country"s largest city endures an extended lockdown to suppress the country"s worst outbreak of this year of the highly contagious Delta variant. New South Wales state Premier Gladys Berejiklian said case numbers would need to drop significantly for the city of 5 million to get out of lockdown, given 28 out of the 65 new infections reported were people who were infectious while still active in the community. "Whilst the case numbers are bouncing around, we are seeing a stabilisation. They are not growing exponentially," Berejiklian said in Sydney. Berejiklian described the new case numbers as a "welcome drop", but warned infections could rise late in the week due to the growing number of people with the Delta strain moving around in the community, particularly in Sydney"s south-west. NSW officials said out of the more than 900 people who have been infected during the latest outbreak, 73 have been moved to hospital, with 19 people in intensive care. Two deaths have been reported, the first for the country this year. Sydney"s lockdown started on June 26 and will remain in place until at least July 30. Authorities say restrictions will only ease when the number of newly reported cases that were circulating in the community while infectious were close to zero. read more VIRUS SPREADS SOUTH The virus has also crossed borders into Victoria and South Australia after an infectious team of furniture movers from Sydney visited both states for work. Dozens of new venues in Melbourne including a shopping centre, two public transport routes and a sporting club were listed late on Wednesday as virus-exposed locations, adding pressure on authorities to tighten restrictions. On Wednesday, mandatory mask rules indoors were reintroduced for Victoria"s more than 6 million residents after the state recorded 10 new cases. read more Two additional cases were reported in Victoria on Thursday. Both people were spectators at an Australian Football League game held in Melbourne"s main sports stadium, the MCG, last weekend. "We"re certainly confident we"re right on the heels of this particular outbreak," said Victoria"s coronavirus response commander, Jeroen Weimar, referring to the system of tracking those who may be exposed to the virus. Curbs on home gatherings and limits for patrons in indoor venues are being considered by the state"s authorities, Australian media reported on Thursday. In South Australia, authorities have identified a third venue visited by the workers, while two regional towns in New South Wales, including one near the border with Victoria and about 500 kms (310 miles) southwest of Sydney, were on alert after the team stopped at service stations. With just over 31,400 cases and 912 deaths since the pandemic began, Australia has handled the COVID-19 crisis better than many other developed countries although its sluggish immunisation drive has taken some of the shine off this success. read more Just over 12% Australia"s adult population of around 20.5 million have been fully vaccinated, with officials pointing to changing medical advice for vaccines and supply constraints.