Police cars and ambulances could be seen outside several diplomatic missions in Melbourne and the capital Canberra, including those of Germany, South Korea, Italy, India, and Spain.
The police said there were ten "hazardous material" responses taking place throughout the city.
"The circumstances surrounding the incidents are being investigated".
Emergency services attended consulates across Melbourne's central busy district and the inner city.
Suspicious packages have been delivered to the British Consulate and other embassies in Melbourne and Canberra, Australian police said. The commission in Canberra was not affected.
The packages were not believed to be risky, but police, fire crews and forensic teams were urged to use breathing apparatus as they documented and double- or triple-bagged the materials for further testing.
"We are liaising closely with the AFP and the local authorities regarding the situation", the spokesperson said.
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Emergency service personal exiting the building where the Korean consulate is located in Melbourne.
On the Emergency Victoria website, there have been more than 13 "hazardous material" alerts listed since 2pm.
The Indian and U.S. consulates on St Kilda Road as well as the British, Swiss and German diplomatic mission are believed to have been targeted.
Addresses for the events included Market Street, Bourke Street, Middleton Lane, William Street, and St Kilda Road in Melbourne, Elgin Street at Carlton, and Yertchuk Avenue at Ashwood.
The ministry said staff were evacuated as a precautionary measure.
Investigating officers at the U.S Consulate on St Kilda Road said the package had been found in the mail room.
The Swiss consulate in Melbourne confirmed to CNN that a suspicious package was delivered at around 1.30 p.m. local time Wednesday (9.30 p.m. Tuesday ET), and that the police and fire services are now investigating.