Satellite images from NASA have shown a "dramatic" drop in pollution levels in China following the coronavirus lockdown.
The images show falling levels of nitrogen dioxide, which is emitted by cars and factories.
"This is the first time I have seen such a dramatic drop-off over such a wide area for a specific event," said NASA researcher Fei Liu, adding that it initially started to drop in Wuhan when roads and businesses were shut.
The images compared the first two months of 2019 with the same period this year.
The agency observed that the decline in air pollution levels also coincided with restriction imposed on transportation and business activities.
Russian air strikes kill 10, injure more than 50 in Ukraine's Kyiv
US, Iran talks conclude in Doha, focused on Strait of Hormuz
Trump honours Theodore Roosevelt in North Dakota, debuts new Air Force One
Kenyan court charges 8 schoolgirls with fellow students' murder
At least 5 people killed in fire in Antwerp apartment block
Three people die in Mexico World Cup celebrations as fans crowd streets
After Venezuela quakes, citizens lead rescues amid military theft accusations
Two dead after wildfire guts house in northern Greece
