Too early to speculate on crash: Bishop

Foreign Minister Julie Bishop says it's too early to blame terrorists for the Russian plane crash in Egypt which killed all 224 people on board.

An Islamic State affiliate has claimed responsibility for the disaster, but both Egyptian and Russian authorities have rejected the claims as investigators probe the crash site in the Sinai Peninsula.

"Until the investigation is completed it will just be speculation," Ms Bishop told ABC radio.

But she noted the irony in Russia's silence on the cause until the results of the investigation were known, given how hostile president Vladimir Putin was to a probe into the MH17 disaster.

"I'm sure the irony won't be lost on people, but now is not the time for me to make such a comment," Ms Bishop said.

A senior official with Russia's Interstate Aviation Committee believes the A-321 broke up in the air, scattering wreckage across a wide area, according to a Russian news agency.

Ms Bishop said no Australians were onboard the doomed flight.

"Our embassies in Cairo and Moscow have been in touch with the local authorities, and can confirm that no Australians were onboard that flight," she told reporters in Melbourne.

She said both black boxes have been found and handed to the Egyptian authorities.