A fan's cap hangs on the fence of the karting circuit owned by seven-time Formula One world champion Michael Schumacher in Kerpen near Cologne, Germany on Monday. [Patrik Stollarz / Agence France-Presse]

Chancellor Angela Merkel joined sports legends and millions of Germans on Monday in expressing shock at Formula One great Michael Schumacher's skiing accident, as his family thanked well-wishers for their support.

In Schumacher's home town of Kerpen, North Rhine-Westphalia, locals were also wishing for a quick recovery for the daredevil racing driver who first honed his skills on his father's local go-kart track as a youth.

"He was always searching for risk and speed," said mayor Marlies Sieburg, adding that "of course he is a fighter, maybe that will help him. His fan club and many residents are concerned not only for the Formula One champion but also for the human being, the man."

The retired seven-time Formula One champion remained in critical condition on Monday, the day after he suffered a severe head injury in an off-course skiing accident in the French Alps.

Merkel declared herself "extremely shocked along with millions of Germans" by the news, according to spokesman Steffen Seibert.

"We hope, along with Michael Schumacher and his family, that his injuries will heal and he will recover," said Merkel. "We wish his wife, his children and the rest of his family strength and mutual support."

Schumacher's wife Corinna and the family expressed their gratitude for the encouragement.

"We would like to thank the medical team who, we know, is doing everything possible to help Michael," she said in a statement.

"We like to also thank the people from around the world who have expressed their sympathy and sent their best wishes for his recovery."

Formula One quadruple world champion Sebastian Vettel, 26, who has said Schumacher was his childhood idol, said: "I am shocked and I hope that he'll be feeling better as soon as possible.

"I wish his family much strength now."

Other well-known German sporting stars took to social media wishing the manknown as "Schumi" a quick recovery.

Tennis legend Boris Becker wrote on Twitter, "Let us all pray for (Schumacher) for a full and speedy recovery !!!", while basketball star Dirk Nowitzki wrote, "My thoughts are with Schumi".

Former tennis star Steffi Graff, a 22-time Grand Slam winner, wrote on Facebook: "Our worries and thoughts are with Michael 'Schumi' and those who are close to him. We wish him a speedy recovery and know that his strength will help him through this difficult situation".

Under the Twitter hashtag #KaempfenSchumi (Fight, Schumi!) many others sent their wishes, including: "Schumi, you must win this race too!"

Michael Viehmann, president of a Schumacher fan club in Kerpen, said: "We're very upset. We know him really well. He's a fighter, we're crossing fingers that he will win this battle."

The co-chairman of the fan club, Reiner Ferling, said the club had received thousands of emails and hundreds of new membership applications since Sunday.

Agence France-Presse