The Chinese capital Beijing issued blue alert on Wednesday as the air pollution blanketed the city.
According to the Beijing Meteorological Bureau, the air quality soared to hazardous levels on Wednesday morning that led to the issuance of blue alert, the lowest level in the four-tier weather alert system.
The visibility range in the city reduced to 2 to 4 kilometres (1.2 to 2.4 miles), with the local authorities advising the citizens to stay indoors.
Additionally, the Beijing's Municipal Environmental Monitoring Center announced that the sandstorm from Mongolia is expected to hit the city during the day.
On Tuesday, orange alert was issued in the city due to the increasing pollution level.
China's alert system which indicates the level of air pollution consists of four phases: blue, yellow, orange and red.
Due to rapid development and industrialization, many of the country's biggest cities rank among the most polluted urban centers in the world.
