Nepal has ordered schools to close for four days after air pollution climbed to hazardous levels, forcing millions of students to stay home across the country.
Nepal, with a population of 30 million people, is located in the Himalayas between China and India, two of the world's biggest polluters.
Air pollution is a chronic problem in the rapidly growing capital city of Kathmandu and an additional headache for the government that is struggling to contain the coronavirus pandemic.
Over the weekend, pollution levels hit their highest in the capital since the government began keeping records in 2016, government official Shankar Paudel told Reuters.
Education ministry spokesman Deepak Sharma said about eight million students have been affected by the closures.
The 24-hour average level of PM2.5, fine particulate matter that can reach deep into the lungs, was 214 micrograms per cubic metre in the upscale area of Bhaisepati in Kathmandu on Sunday, Department of Environment data showed. That compares with the government's standard level of 40 micrograms per cubic metre.
Air quality in the capital has deteriorated recently but average pollution readings were not available.
Dust from construction works, exhaust from old, poorly maintained vehicles and smoke from coal-burning brick kilns blend in a murky haze that hangs over the ancient city of four million people, raising the risk of cancer, stroke, asthma and high blood pressure, experts say.