The Victorian Health Department confirmed the finding on Friday, April 29, and said authorities would now prioritize the sequencing of PCR samples from COVID-19 cases in the water catchment area to get a better understanding of the spread of the BA.2.12.1.

"Early evidence suggests it is more transmissible than BA.2 but does not cause more severe disease," the health department said.

The BA.2.12.1 sub-variant is currently on the rise in the United States, which makes up nearly 30 percent of sequences identified nationally, according to the Centers for Disease Control and Prevention, and is also fast spreading through Europe.

Victoria reported 19 COVID-related deaths on Saturday along with 9,064 new cases, bringing the state's overall active cases to 54,992.

There are 448 Victorians hospitalized with COVID-19, 30 of whom are in intensive care units.

The BA.2.12.1 detection came only a day after the first case of another Omicron sub-variant, BA.4, was found in the neighboring state of New South Wales (NSW) with a traveler from South Africa.

The sudden simultaneous arrival of the two virulent strains is already causing concern among medical experts such as epidemiologist Professor Adrian Esterman from the University of South Australia.

"BA.2.12.1 now accounts for 25 percent of cases in the U.S. BA.4 is rapidly becoming the dominant strain in South Africa. Increasing case numbers will inevitably result in increased hospitalizations and more people with long-COVID. This is real and happening now," Esterman tweeted on Friday.

Speaking to local media Channel 7 News the same day, Esterman said BA.4 "appears to escape the immune system a bit better than BA.2, so that means that people who've already been infected can be re-infected more easily, and people who are vaccinated can be infected more easily."

"This comes just at the stage where we're removing all our public health measures - that's the bad news," he said.

Meanwhile, NSW recorded 11,709 new COVID-19 cases and 20 deaths in the 24 hours till 4:00 p.m. Friday local time. There are 1,623 cases in the hospital, with 69 in ICU.

Read: New Zealand Reports 1st Case of Omicron XE Variant

Xinhua