The deaths add to the toll in the French mountains from avalanches since Friday.
Interior Minister Gerard Collomb, on Twitter, urged all those taking part in winter sports to act "with the utmost caution."
It is essential to follow the signs put up by local authorities "to avoid putting yourself in danger and endangering rescue teams".
The two skiers died during simultaneous avalanches around lunchtime, while skiing off-piste from the Vallorcines resort in the Chamonix-Mont Blanc region.
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Another Belgian in the same group was injured.
An hour earlier, at Samoens near the Swiss border, a Swiss hiker was swept away by another avalanche. Bad weather forced searchers to abandon their efforts to find him later in the day.
The man's wife was also buried in snow but escaped with only minor injuries.
"We are pessimistic about his chances as he has already been five hours under the snow, " an Haute-Savoie regional official told AFP yesterday.
On Saturday two Spanish skiers were killed when an avalanche hit a group skiing off-piste on a mountain in southeastern France.
A day earlier four skiers were killed in the Mercantour National park in the French Alps, the deadliest avalanche of the winter so far.