Hair-raising footage of the incident, posted online by Harry Shimmin, one of those on a trek in the mountains, shows snow rushing down the mountain-side towards the group.
In an explanation of what happened on Instagram, Mr Shimmin said he had broken off the group to take pictures from the highest point on the trek when the avalanche happened.
“While I was taking pictures I heard the sound of deep ice cracking behind me. This is where the video starts,” he said.
He dived to safety in a spot next to him which was behind the rock, but told of his fear that he might die.
“Yes I left it to the last second to move, and yes I know it would have been safer moving to the shelter straight away. I’m very aware that I took a big risk,” he said.
“I felt in control, but regardless, when the snow started coming over and it got dark / harder to breath, I was bricking it and thought I might die.”
According to Mr Shimmin, the group only reported some injuries but were safe, with one tourist cutting her knee and the other suffering mild bruising. The group were “laughing and crying, happy to be alive”, he said.
“Behind the rock it was like being inside a blizzard. Once it was over the adrenaline rush hit me hard,” he said.
“I was only covered in a small layer of snow, without a scratch. I felt giddy. I knew the rest of the group was further away from the avalanche so should be okay.
When I re-joined them I could see they were all safe, although one had cut her knee quite badly (she rode one of the horses to the nearest medical facility).”
The Tian Shan mountains are a range of mountains in central Asia which formed part of the historic Silk Road trading route.