French police say the man and 12-year-old boy were exploring a "dangerous, deep, snowy" mountain trail between Bossons and Les Houches.
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An off-duty military policeman in Brazil killed two suspected robbers in a pharmacy while holding his young son in his arms.
A police spokesman said the young man detonated his explosives while mingling among the worshippers.
A scheme to test potential cancer patients at mobile units in shopping centre car parks is to be expanded.