A magnitude-3.8 earthquake in Sunbury, west of Melbourne, has been felt across the region but there have been no reports of damage.
Melbourne residents reported buildings shaking on Sunday evening about 11:41pm.
Although Sunbury is 40 kilometres north-west of the city, the earthquake's impact was felt in Melbourne's CBD.
The quake, which occurred at a depth of 3 kilometres, lasted only a few seconds, according to residents.
More than 20,000 people in Sunbury had reported feeling the earthquake to Geoscience Australia by about 1:30am.
The tremor was also felt as far north as Bendigo and as south as Hobart.
Victorian SES chief operations officer Tim Wiebusch said many people reported feeling the tremor, but there were no reports of damage to buildings or injuries.
"The size that we're talking about at a 3.8 it's typically, definitely felt indoors by many and also by those outdoors," he told ABC Radio Melbourne.
"You would hear that sudden rush like a train noise that some people experience but it has been widely felt all the way from Geelong to Ballarat, out to Seymour, down on the Mornington Peninsula and as north as Murchison."
Geoscience Australia seismologist Hugh Glanville said the tremor would have been widely felt but would have been unlikely to damage infrastructure.
"While it's stronger shaking that travels a decent distance throughout the region, we don't expect damage from an earthquake of that size," he said.
"You don't tend to get minor damage until around magnitude 4.5 where you'll get things like plaster cracking and things rattling on shelves."
He said more tremors were possible over the next couple of days.
"We could expect aftershocks from an earthquake of this size, it's not guaranteed of course, sometimes you just get a single earthquake and no aftershocks associated," he said.
Adam Pascale, chief scientist at the Seismology Research Centre (SRC), said the earthquake may have been the largest in over 100 years within the Melbourne metropolitan area.
"The last earthquake above a magnitude 4 in the metro area was in 1902," Mr Pascale said in a video posted on Twitter.
Dee Ninis from the SRC said people close to the epicentre reported hearing an explosion.
"This looks to have been a shallow event — the seismic energy produced by such earthquakes can reach the surface to transform into sound waves, making a 'boom'," she tweeted.
Melbourne was rattled by an earthquake in September 2021, which caused some damage, including on the famous Chapel Street shopping strip.
At magnitude 5.9, it was the largest earthquake ever recorded in Victoria, but its epicentre was at Woods Point, about 130 kilometres east of Melbourne.
The 2021 tremor was also felt in parts of New South Wales, South Australia, Tasmania and the ACT.
On average, Australia experiences around 100 earthquakes of magnitude 3 or larger each year, according to Geoscience Australia.
Earthquakes above magnitude 5, such as the destructive magnitude-5.4 earthquake in Newcastle in 1989, occur approximately every one to two years.
