Beijing was battered by its first sandstorm of the year coupled with strong winds and smog on Thursday, reigniting debate over doubling fines for the city's biggest polluters. Elsewhere in North China, other cities were also left reeling from similar hazardous weather.

However, the China Meteorological Administration's (CMA) forecast over the next 10 days shows signs of improvement to air quality in Beijing, with smog set to ease amid a building cold front.

CMA director Chen Zhenlin told reporters at a press conference on Thursday that the administration will provide more accurate air quality reports with the help of satellite systems, noting efforts have also been made to improve weather forecasting efficiency.

Data from the Beijing Municipal Environmental Monitoring Center showed readings for PM2.5, airborne particles measuring 2.5 microns or less in diameter, soared to 500 micrograms per cubic meter by 11 am on Thursday in many districts of the city.

Beijing's noxious haze saw the US embassy's air quality index reading hit 516 at 6 am, signaling worse air quality than the highest warning of "hazardous," according to AFP.

Local meteorological departments advised residents to wear warm clothes and stay indoors.

Those who ventured out mid-morning were confronted by swirling clouds of dust, which the Beijing Municipal Environmental Monitoring Center said had been blown in from the Inner Mongolia Autonomous Region.

Legislators are considering doubling the maximum fine for companies that violate emission regulations to 1 million yuan ($160,700), reported the Economic Information Daily.

The Ministry of Environmental Protection, State Council and National People's Congress are mulling a draft to amend the Prevention and Control of Atmospheric Pollution Law. If consensus can be reached and such a move goes ahead, it will be the third such amendment to the law in 13 years, the newspaper reported.

The current law caps fines at 500,000 yuan, which some legislators believe poses a weak deterrent to heavy polluters.

Meanwhile, neighboring Tianjin was also shrouded in dense smog on Thursday. The city's meteorological observatory has issued two separate yellow alerts, the second-lowest level in China's four-tier, color-coded weather alert system, for smog since Wednesday.

Statistics from the Tianjin Environmental Bureau showed that the concentration of PM2.5 at seven of the city's 27 monitoring stations had exceeded 300 micrograms per cubic meter on Thursday.

Sections of 15 expressways passing through Tianjin were temporarily closed on Thursday due to poor visibility.

Sandstorms and gale-force winds also swept parts of the Inner Mongolia Autonomous Region. Among cities hardest hit were Hohhot and Baotou as well as the Ulanqab, Xilin Gol and Bayannur leagues, where visibility and temperatures plummeted and air quality was hazardous.

The grim weather and air quality has been a hot topic of discussion on microblogging service Sina Weibo, where more than 13.4 million sandstorm- and smog-related posts have been uploaded over the past month.

Global Times - Xinhua