China's second-strongest sandstorm so far this year is expected to continue until the end of this week, forecasters said.

The sandstorm, which is understood to have originated in Mongolia and has hit many parts of the country, started on Sunday and has led to the closure of scenic spots and affected transportation in some areas.

It is forecast to spread from Northeast China's Heilongjiang province to as far south as the Yangtze River Basin, causing heavy airborne pollution and low visibility.

The Inner Mongolia autonomous region has borne the brunt of the sandstorm. China News Service reported that visibility was less than 1,000 meters in the Juungar Banner of Ordos, Inner Mongolia, prompting motorists to use their fog lights.

In Beijing, the city's Culture and Tourism Bureau issued a notice on Monday reminding managers of scenic spots to suspend the operation of outdoor amusement facilities such as ropeways and slides.

In addition, construction firms were urged by the city's Forestry and Parks Bureau to cover exposed areas at construction sites, strengthen safety supervision and suspend all work at heights such as lifting, hanging and climbing.

All work at a construction site owned by China Construction Science and Industry Co's Beijing company in Changping district has been suspended until the sandstorm alert is lifted.

The Beijing Ecological and Environment Monitoring Center forecast on Tuesday that air quality in the city will improve on Wednesday, with the level of PM10 — inhalable particles with a diameter of 10 micrometers or less — dropping below 165 micrograms per cubic meter.

On Tuesday, the National Meteorological Center renewed its blue alert for sandstorms nationwide — the lowest level of alert in the four-tier weather warning system.

The PM10 level reached a concentration of more than 2,000 micrograms per cubic meter in most parts of northern China, the center said.

The PM10 level usually remains below 150 micrograms per cubic meter when the air quality is good.

The center added that the sandstorm will last until the end of this week.

Gui Hailin, the center's chief forecaster, said the heat and lack of rain in northern China in spring result in more exposed sandy surfaces.

In addition, cyclonic activity brings more wind that lifts up the particles, he said.

"We must maintain a scientific attitude on the issue of eradicating sandy and dusty weather," Gui said, adding that efforts should be focused on preventing the expansion of sandy areas.

Since the beginning of this year, China has experienced eight rounds of dusty weather, which is more than normal, according to the National Meteorological Center.

It added that this weather occurs most frequently and heavily in April.

The last sandstorm, which was the strongest so far this year, was in late March, according to the center.

Last spring, northern China had eight rounds of dusty weather. From 2000 to 2021, there was an annual average of 10.7 rounds of dusty weather, according to the 2022 China Climate Bulletin.