WARSAW (AFP) -- Doctors in Poland on Wednesday began attempts to bring Czech ski jumper Jan Mazoch out of an artificial coma, five days after his horrific fall during a World Cup event.

"He underwent a scan at noon. His doctors decided that his condition was such that they could try to take him out of the coma," said Anna Niedzwiedzka, spokeswoman for Krakow university hospital.

"The operation will take more than 10 hours. On Thursday (this) morning, his doctors will again check his condition and decide how his treatment should continue," Niedzwiedzka was quoted as saying by the Polish news agency PAP.

Mazoch, 21, who was competing in his first World Cup event of the season in the southern Polish resort of Zakopane, was knocked unconscious when he fell after losing his balance in the middle of a jump.

Windy conditions were thought to have been to blame.

Mazoch fell heavily on his back and face before ending up at the bottom of the landing zone. The second round of jumps was promptly canceled.

After receiving initial treatment at Zakopane's hospital, Mazoch was transferred to the specialized neurological trauma department in the southern Polish city of Krakow, where doctors decided to keep him in an artificial coma.