At least 21 people have died due to a “mysterious disease” in northeastern Afghanistan, officials said on Sunday.

The disease spread in the Wakhan area of the mountainous Pamir region, where medical teams are working to determine the exact nature of the illness, according to local authorities in Badakhshan province.

So far, 21 people have died in the last two weeks, they added, while the Ministry of Health of the interim Taliban administration said the medical teams reached the region via neighboring Tajikistan.

Turkic-speaking Kyrgyz people live in the eastern Pamir region of Afghanistan, which borders China, Pakistan, and Tajikistan, while ethnic Tajiks live in the western valleys.