SYDNEY, July 20 (Reuters) - Two of Australia's six states were in lockdown on Tuesday as the COVID-19 Delta variant spread, with Victoria extending its lockdown for seven days and South Australia announcing a week long lockdown, while Sydney was in a five-week lockdown.
Australia's most populous state New South Wales (NSW), of which Sydney is the capital, is battling the largest COVID-19 outbreak, with total cases exceeding 1,400.
NSW authorities reported a slight slowdown in new cases on Tuesday, with the state in its fourth week of lockdown. NSW reported 78 locally acquired cases, down from 98 a day earlier.
"We are seeing more hospitalisations, more admissions to ICU, more people on ventilators - we have to stop the spread of COVID," NSW Chief Health Officer Kerry Chant said in Sydney on Tuesday, referring to intensive care units (ICU).
At least 21 of the new cases were infectious while still in the community, a number that authorities said must be close to zero in order for lockdown restrictions to be lifted.
A five-day snap lockdown in Victoria state was due to end Tuesday night, but authorities said the lockdown would need to be extended seven days.
"There are chains of transmission that are not yet contained that we don’t know about and if we would open up we would see how quickly this runs, we see how challenging this can become in a very short space of time," Victoria's Premier Daniel Andrews said in Melbourne on Tuesday.
"The speed with which this has moved through the Victorian community confirms that we did the right thing to lock down, and it also sadly confirms that we need more time."
Nine locally acquired cases were detected in Victoria from 13 a day earlier, in line with a downward trend and taking total cases to more than 80. Of the new cases, all but one was linked to the current outbreak, officials said.
Virus-exposed locations in Victoria have risen to more than 300 since the first cases were detected a week ago linked to a team of infectious furniture movers from Sydney.
The state of South Australia entered a snap seven-day lockdown after identifying new Delta cases. Authorities have so far identified five cases linked to the current cluster.