Four people were killed and nine others were injured in an avalanche southwest of Mont Blanc in the French Alps on Sunday, according to interior minister Gerald Darmanin.

He tweeted that the avalanche happened in the middle of the day on the Armancette glacier.

Those involved were backcountry skiing in the mountains, according to Emmanuel Coquand, a spokeswoman for Haute-Savoie authorities, who added that the identities of the victims were still being confirmed.

He said the avalanche was extensive, covering an area of one km by 500 metres (half a mile by 550 yards) at an altitude of 3,500 metres and that its causes are being investigated.

The glacier lies near the village and ski resort of Les Contamines-Montjoie.

President Emmanuel Macron wrote on Twitter that rescue services were continuing to search for further casualties and that his thoughts were with the victims and their families.