Nimral Purja, known from the Netflix series "14 Peaks: Nothing Is Impossible" in which he climbed the world's 14 highest mountains in seven months, is among those missing, several media outlets report.
The avalanche is said to have been triggered around lunchtime on Thursday and the group has not been able to be contacted since then.
According to BBC sources, a search operation on the 8,047-meter-high mountain will begin on Friday.
