Iran responded with drone and missile strikes targeting Israel, as well as Gulf states like the United Arab Emirates, Bahrain and Qatar.
The attacks have forced busy Gulf hubs, including Dubai and Doha, to suspend flights, leaving passengers stranded around the world.
Australia backed the US-Israeli strikes as necessary to prevent Tehran from acquiring nuclear weapons.
It has a small military presence in the Middle East – around 100 personnel, many stationed at the Al Minhad base in the UAE.
Officials have said Canberra has no plans to take part in any military action against Iran.
But the country has close military ties with the United States.
As of last month, around 70 Australian military personnel are currently serving on American nuclear submarines, Canberra has said.
Prime Minister Anthony Albanese has said that three Australian personnel had been on board a US submarine when it sank an Iranian ship on Wednesday (local time).
The personnel were on the submarine as part of training arrangements under Aukus, a multi-decade defence pact with Britain and the United States, Albanese said.
– Agence France-Presse