Michael Schumacher has shown slight improvement: Doctors

Michael Schumacher has shown 'slight improvement' after surgical procedure, doctors updated from Grenoble University Hospital on Tuesday.

The intervention took around two hours, and the coming hours are 'critical' according to medical staff. They have refused to be drawn on future predictions on the driving ace's condition.

"This is still a fragile situation, we can still say it is a critical one," said one of his doctors.

The family of seven-time Formula One world champion Michael Schumacher is at his bedside as he fights for life following a skiing accident in the French Alps.

-Alpine skiing top official sees Michael Schumacher recovery chance

Schumacher's manager, Sabine Kehm, said his wife, Corinna, daughter Gina Maria and son Mick are in a state of shock at the Grenoble hospital, the BBC reported.

The German was fighting for his life on Monday after suffering severe head injuries in a skiing accident in the French Alps resort of Meribel, doctors said.

"We can say that his condition is life-threatening," Jean-Francois Payen, head anaesthetician at the CHU hospital in the eastern French city of Grenoble, told a news conference.

The retired motor racing great, 44, was skiing with his 14-year-old son on Sunday morning in the resort of Meribel when he slammed his head on a rock while skiing off-piste.

Philippe Quincy, the Albertville public prosecutor, said an inquiry had been launched on Sunday to identify the causes of the accident. Initial findings indicated the blow was so hard that Schumacher's helmet had shattered.

A spokesman for German Chancellor Angela Merkel said she was shocked to hear the news.

"We hope that he overcomes his injuries and can recover," the spokesman told a regular briefing in Berlin.