All diplomatic missions in Australia were warned to be on the lookout for suspicious packages before envelopes appearing to contain asbestos were found at consulates in Melbourne, the Department of Foreign Affairs and Trade (DFAT) says.
The US, Pakistani, New Zealand and Swiss consulates confirmed they received the suspicious packages on Wednesday.
Emergency services workers were also seen at the Greek, French, Italian, Indian, Spanish and South Korean consulates.
One official from Pakistan's consulate told the ABC she opened an envelope which appeared to contain asbestos and she was "scared of what might happen".
Hazardous material alerts were issued for more than a dozen locations across Melbourne, including a South Melbourne building where the Consulate General of Turkey is based.
DFAT said three similar incidents recently occurred in Sydney and Canberra, and the ABC understands that the Argentinian consulate in Sydney was sent three bags containing asbestos and fibreglass on Monday.
DFAT said in a statement that these events prompted it to notify all diplomatic missions on Tuesday to be cautious with their mail.
In a statement, it said:
"After learning of incidents at three offices in Sydney and Canberra, DFAT sent a note to all diplomatic missions in Canberra on 8 January alerting them to the possibility of suspicious packages being delivered by mail.
"The note advised missions to handle mail in accordance with their own Government's protocols and instructions.
"It also included Australian Federal Police (AFP) guidance on handling suspicious mail and advised missions to contact the AFP Protection Liaison Team to report any concerns or incidents.
"Similar advice was subsequently provided to consulates around Australia."
The Australian Federal Police said it is investigating.
Ambulance Victoria said it did not need treat any patients at consulates in Melbourne yesterday.
