By Lex Harvey, Ross Adkin, Xiaoqian Lin, Sophia Saifi, CNN(CNN) — A search to find the rest of group of missing climbers, including world-renowned mountaineer Nirmal Purja, continues in Pakistan, following an avalanche that killed at least four of them. Rescuers, though, told CNN on Saturday that they are concerned about the prospect of another avalanche occurring. Along with 43-year-old Purja and American Geis, the group included climbers from Oman, Pakistan and Nepal, according to the Alpine Club. Purja, also known as “Nims,” made history in 2019, climbing all of the world’s 14 peaks over 8,000 meters (26,300 feet) in just over six months. His feat was chronicled in the hit Netflix documentary “14 Peaks: Nothing Is Impossible.”