Vehicles run in smog in Beijing, capital of China, Oct. 6, 2015. China's central observatory on Tuesday issued a yellow alert for smog to hit parts of north China, including Beijing, on Tuesday and Wednesday. (Photo: Xinhua/Liu Xianguo)
China's weather observatory on Tuesday afternoon continued to issue a yellow alert for smog in Beijing and neighboring regions.
Smog in Beijing, Tianjin and parts of Hebei, Liaoning and Shandong provinces since Monday may persist, the National Meteorological Center (NMC) said.
The smog will be dispersed by a cold front from Wednesday evening, the NMC said.
China has a four-tier color-coded weather warning system, with red representing the most severe weather, followed by orange, yellow and blue.
The NMC warns people in the affected areas to reduce outdoor activities.
The smog coincides with the week-long National Day holiday, and many tourists are vacationing in Beijing.
The Chinese public have become increasingly sensitive to the health hazard. To address public concerns, the government aims to cut the density of inhalable particulate matter by at least 10 percent in major cities by 2017.