The two Australians among the 150 people killed in the Germanwings plane crash were from Melbourne, Victorian Premier Daniel Andrews has confirmed.

The woman and her adult son were were on board the Airbus operated by Lufthansa's budget airline Germanwings, which was travelling from Barcelona in Spain to Dusseldorf in Germany. It crashed in a snow-clad alpine area in the French Alps.

"We can confirm that two of the 150 who have lost their lives are from our state, and we believe they're from Melbourne," Mr Andrews told reporters on Wednesday.

"I think all Victorians are very sad to wake up to this tragic news.

"This is a great tragedy; it's very, very sad news for all of us. Our thoughts, our prayers, our best wishes and our support, most importantly, will be with that family."

Mr Andrews said he was unable to provide any further information about the two Victorians, but would personally contact their family at an appropriate time.

He also said the accident would be a "painful reminder" for those affected by recent air disasters, especially the shooting down of MH17 and the disappearance of MH370.

"This incident will be a very painful reminder of other disasters in recent times - whether it's MH370 or MH17 - this will be a very raw moment for many Victorian families who have had to live through those tragedies just in the space of the last 12 months," he said.

Foreign Minister Julie Bishop revealed that two Australians had been on board the doomed flight during a snap press conference on Wednesday morning.

"It would not be appropriate to disclose further details of our citizens at this stage due to the privacy considerations of the family," Ms Bishop said.

She said consular officials would travel to the small town of Gap near the crash site to liaise with French authorities.

"I understand that the French interior minister is travelling to the site tomorrow morning, as in French time, and they will be setting up an incident coordination centre and we intend to be there," she said. "We'll set up a mobile office at that point and as many consular staff are as needed will travel."

Ms Bishop said it would be premature to speculate about the cause of the crash, but noted that Lufthansa was working on the assumption it was an accident.

Prime Minister Tony Abbott also confirmed the news in Canberra.

"There's been another air disaster involving Australians," he said. "Our thoughts and prayers are with the friends and families of all those killed, particularly with the loved ones of the two Australians who have lost their lives.

"Our consular officials are doing what they can for the families."

Opposition Leader Bill Shorten was shocked by the news.

"Devastating news from France of the Germanwings flight from Barcelona. Absolutely heartbreaking," he tweeted.

French Interior Minister Bernard Cazeneuve said that one of the black boxes from the plane had been found.

More to come.