At least 21 people, most of them children, have died from a contagious respiratory illness in northeastern Afghanistan over the past two days, an official said Tuesday.

The illness was not immediately identified.

The victims in the remote Koof district of Badakhshan province died as a result of respiratory conditions, said Ghafour Dawar, head of public health in Faizabad, the provincial capital.

“We are concerned about it. It seems the disease is a contagious one,” he said, without elaborating.

Dawar said heavy snowfall in Koof meant that doctors could only reach the area through neighboring Tajikistan.

The deaths bring the number of people who have died of illnesses caused by harsh winter weather in Afghanistan in the past month to nearly 100.