Sydney woman's boyfriend shot in attack

An Australian woman whose French boyfriend was shot when gunmen stormed the Paris office of Charlie Hebdo says he's in a coma.

Maisie Dubosarsky, 27, flew out of Sydney for Paris on Thursday to be with her boyfriend, Simon Fieschi, 31, who was one of ll people injured in the attack at the office of the Paris-based satirical magazine on Wednesday.

Twelve people were killed in the assault that has shocked France and been condemned by leaders worldwide.

Speaking on Thursday, Ms Dubosarsky said Mr Fieschi was in a critical condition in hospital.

"They've operated on him," she told ABC television.

"(He) got shot through the shoulder. We don't know if he's going to have like problems walking. We're going to keep him in the coma at least another day or so."

She said the bullet, after entering his shoulder, had "perforated a lung and the ricochet has gone off his vertebrae".

Mr Fieschi's condition would be unclear until he was "out of this coma", Ms Dubosarsky said.

The 27-year-old, who met Mr Fieschi while on a working holiday in France, said she initially thought her boyfriend was dead when she heard of the attack.

"Thirty minutes later, his mother contacted me and said he was alive and that was like the best news I have ever heard," Ms Dubosarsky said.

Mr Fieschi reportedly handled the social media accounts of Charlie Hebdo, which is known for its provocative satire of religious figures, including the prophet Mohammed.

President Francois Hollande declared a day of national mourning on Thursday in response to the worst attack on French soil in decades.

A manhunt continues across France for those responsible for the massacre.