Sirbaz, 32, hails from the Aliabad area of Hunza in Gilgit-Baltistan and began his climbing career in 2016. Sirbaz is aiming to become the first Pakistani to climb all 14 of the world`s highest peaks.
A senior official told AFP that Canadian Richard Cartier and Australian Matthew Eakin were missing on K2, while Briton Gordon Henderson was lost climbing Broad Peak. "We cannot declare them dead until the bodies are found."
The Gilgit-Baltistan tourism department has already issued 700 permits to international climbers, and as many were expected to be issued this summer, an official told Dawn.
A Nepali Sherpa broke her own record reaching the 8,849-meter (29,032-foot) summit for the 10th time - the most times any woman has climbed Mount Everest.
The two — Shehroze Kashif, who last year scaled K2 at age 19, and Fazal Ali — went missing on Tuesday after scaling Nanga Parbat, known as “Killer Mountain” because of its dangerous conditions.
The 31-year-old Samina reached the top of the 8,611-metre peak early on Friday as part of a seven-member local team, and was followed hours later by a second Pakistani woman, Dubai-based Naila Kiani.