Pakistani mountaineers Sirbaz Khan and Naila Kiani on Monday summited the sixth highest mountain in the world, Cho Oyu, the non-governmental sports organization Alpine Club of Pakistan confirmed in a statement.

Standing at an imposing height of 8,188 meters or 26,906 feet high, Cho Oyu is located on the Nepalese–Tibetan (Chinese) border about 20 miles (30 kilometers) northwest of Mount Everest. According to Karrar Haidri, secretary of the Alpine Club of Pakistan, it took both mountaineers 28 hours to summit the treacherous mountain amid challenging conditions.

“Sirbaz has accomplished an amazing accomplishment by ascending Cho Oyu, 8,188 meters high and the sixth highest peak in the world, in over 28 hours via a marathon alpine style climb,” Haidri told Arab News over the phone, adding that Khan is the first Pakistani climber to summit Cho Oyu.

“He achieved this feat without the need for additional oxygen, which makes it even more amazing.”

Khan’s latest feat makes him the only Pakistani climber who has summited 13 out of a total of 14 mountains that stand above 8,000 meters high, which are also known as “eight-thousanders.” These mountains are all located in the Himalayan and Karakoram mountain ranges – across Nepal, Tibet (China) and Pakistan.

“There is still one summit left on his trek, this being the thirteenth successful one,” Haidri said.

Haidri praised Kiani for becoming the first Pakistani woman to summit Cho Oyu, saying that she was able to achieve the feat in “incredibly challenging conditions with very poor visibility and hostile weather.”

“We all hope and pray for Naila’s safe return from this extraordinary adventure,” Haidri said, adding that with the latest feat, Naila successfully climbed her 10th eight thousander.

Kiani’s X account updated her followers with her achievement, saying that she became the first Pakistani with Khan to summit Cho Oyu.

“First Pakistani woman to summit 10 8,000er, only Pakistani to summit 7 8,000er in six months,” Kiani’s account wrote.

Kiani, Khan and mountaineer Shehroze Kashif summited Mount Manaslu in Nepal last month, which is the eighth-highest mountain in the world. Mount Manaslu stands at an imposing height of 8,163 meters above sea level.