Australian Federal Police (AFP) and emergency services were investigating "suspicious packages" delivered to embassies and consulates in Canberra and Melbourne on Wednesday.
The diplomatic missions in Melbourne include Indian, French, Korean, Swiss and German ones, according to authorities. It is not clear which embassies in Australia's capital Canberra were affected.
Melbourne's fire brigade said it was responding to a number of calls involving hazardous materials across the city. It said the incidents are "under control."
Emergency Victoria on its website listed more than 10 "hazardous material" responses taking place across Melbourne.
Victoria Police also confirmed that several consulate offices in Melbourne on Wednesday received suspicious packages.
"At this time we believe the matter is targeted and not impacting the general community," Victoria Police said, adding it was assisting the federal police and other agencies with the investigation.
More than 10 diplomatic offices in Canberra and in Australia's second-largest city Melbourne were targeted by a series of packages of unknown origin, local media reported.
The suspicious packages sparked a major emergency response and evacuation as the diplomatic missions were put on lock-down and workers, including diplomatic staffs, were evacuated from the buildings attended by police, fire crews, hazmat teams and ambulance officers.
Staff evacuated from the Indian Consulate in Melbourne told reporters they had been asked not to comment.
Peter Erb, the husband of Swiss honorary consul Manuela Erb, told dpa the diplomatic mission in a Melbourne suburb had received a small envelope through regular Australia Post on Wednesday afternoon.
"Inside the envelope was a white material in plastic with a label: 'asbestos'," Erb said. "We put the envelope in another plastic bag and called the emergency service, who arrived within 10 minutes."
He said the content of the envelope was not bio-hazardous in nature.
"It is not something that we have ever known to have received. In fact, we don't know if anyone in the Melbourne consular district has ever received such a threat," Erb said, adding that the consulate was still closed to the public.
"You have to treat these things as serious, until they are not."
On Monday, the Sydney-based Argentinian consulate was evacuated for more than an hour after reports of a suspicious white powder. It was later deemed not dangerous.
