An avalanche in the French Alps has killed nine people and searches were under way to find several missing people, the Paris government has said.

The avalanche, which swept down a mountainside in the Mont Blanc range near the border with Switzerland on Thursday also injured 11 people, Manuel Valls, the interior minister  said in a statement.

Valls said the death count was preliminary, and did not specify how many people remained unaccounted for.

A group of 28 climbers from Switzerland, Germany, Spain, France, Denmark and Serbia were believed to be in the deadly expedition on Europe's highest mountain.

A police source had told the Reuters news agency earlier that two or three people were missing.

BFM television reported that the deceased were of different nationalities, with at least one French citizen killed.