A powerful yellow dust storm blanketed almost all parts of South Korea on Monday, local media reported.
Citing the Korea Meteorological Administration, Yonhap News Agency said the storm originated in the Inner Mongolian region in northern China and the vicinity of the Gobi Desert on Friday and moved south by riding northwesterly winds.
The density of fine dust particles smaller than 10 micrometers in diameter, known as PM 10, surged to the "very bad" level in the greater Seoul area and all other regions, they agency quoted local authorities as saying.
Authorities have advised the people with respiratory or cardiovascular problems, children and other vulnerable people to refrain from going outdoors.
This is the second dust storm over the last two weeks.