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.
Man charged with 10 counts of attempted murder after knife attack on UK train
Tanzania's Hassan sworn into office after deadly election violence
Powerful 6.3 quake kills at least 20 in Afghanistan, hundreds injured
Turkey set to call for action on Gaza as soon as possible, source says
Hamas hands over three more hostage bodies
