GRENOBLE, FRANCE (Reuters) - The medical condition of seven-time Formula One champion Michael Schumacher is slightly better on Tuesday, following a second operation during the night to treat head injuries sustained in a skiing accident, doctors said.

"The situation is more under control than yesterday but we cannot say that he is out of danger," Jean-Francois Payen, head anaesthetician told a news conference at the CHU hospital in the eastern French city of Grenoble where Schumacher is being treated.

"We have won some time but we must continue an hour-by-hour surveillance."

Schumacher suffered head injuries on Sunday in a skiing accident in the French Alps. The German was subsequently put in a medically-induced coma, reported BBC Online.

Late on Monday night doctors carried out a new scan on Schumacher which showed "an improved situation" and indicated a window of opportunity for a second operation.

The family took the "difficult decision" to give consent for the operation, and doctors operated on Schumacher for about two hours.

A subsequent scan revealed a "slight improvement" in Schumacher's condition.