"The avalanche hit on Sunday morning," he said.
The missing people are from different expedition companies. Expedition and rope-fixing teams had evacuated the mountain slopes after a weather warning was issued last week, but some people stayed back despite the warning.
Heavy snowfall forces climbers to retreat
The Himlung Himal region has received heavy snowfall for several days, forcing climbers to retreat from the autumn ascent of the 7,126-metre peak in Manang district.
Himlung Himal is a popular climbing destination for those seeking experience at high altitude. Helicopter flights to the mountain also require an additional permit, making access to the area more difficult.
Don't Miss: El Niño's weather paradox: How one climate event causes floods and droughts
The latest avalanche comes amid deteriorating weather conditions across Nepal. A weather system over the Bay of Bengal has brought heavy snowfall to mountainous areas and persistent rainfall to the country's hills and plains.
Chitwan's Madi Kalyanpur recorded Nepal's highest rainfall over the past 24 hours, with 222.4 mm measured at the local weather station, according to the Meteorological Forecasting Division (MFD), The Kathmandu Post reported.
The MFD said heavy to very heavy rain was recorded in parts of Madhesh, Gandaki, Lumbini, Bagmati and Sudurpaschim provinces. Many parts of Koshi and Karnali also received light to moderate rain.
Nepal issues weather alert for trekkers, climbers
Nepal has been witnessing adverse weather conditions since Friday, disrupting roads and prompting local authorities to close several sections to traffic.
Tourism authorities have urged trekkers and climbers to suspend activities as weather conditions worsen. The Department of Tourism has also issued an alert advising that tourism activities be put on hold.
Persistent rain and snowfall have disrupted several trekking routes and forced the cancellation or suspension of major expeditions on Manaslu and Dhaulagiri.
The weather disruption follows last month's devastating floods in Rasuwa, which killed more than 1,400 people and left more than 5,000 missing. The floods washed away settlements along the Trishuli River and dealt another blow to Nepal's tourism industry.
Must Read: What makes an El Niño ‘super’ – and why this one could be especially severe
Himlung avalanche follows Broad Peak tragedy
The latest incident comes weeks after an avalanche on Pakistan's Broad Peak killed 10 climbers, including three of Nepal's high-altitude guides and climbers.
In August, the remains of Kili Pemba Sherpa, also known as Kilu, along with Gyalu Sherpa and Nima Sherpa, were brought back to Nepal.
The three were among 10 climbers killed when an avalanche struck at around 9:30 am on July 30 as the group climbed between Camp 2 and Camp 3, at roughly 6,600 metres on the 8,051-metre Broad Peak in Pakistan's Karakoram range.
The entire 10-person international team died in the incident. Those killed included British-Nepali climbing star Nirmal Purja, also known as Nimsdai; Pur Bahadur Gurung; Nawang Thindu Sherpa; Omani climber Nadhira Al Harthy; Chinese climber Wang Zhong; Pakistani guide Sohail Sakhi; and American climber Mallory Geis.
(With inputs from ANI)