For the first time since it introduced an emergency smog alert system last October, the Beijing government issued its second-highest warning level - an "amber alert" on Friday, repeating the warning on Monday.
Pollution-weary residents of smog-hit Beijing turned to black humour to help cope with gruelling conditions as a large swathe of China was covered by a thick blanket of haze for a sixth consecutive day.
Meanwhile on Tuesday President Xi Jinping was pictured taking a walk on a Beijing street, in the latest instance of Chinese authorities seeking to portray themselves as close to ordinary citizens.
Small airborne particles, which easily penetrate the lungs and are known as PM 2.5, have been linked to hundreds of thousands of premature deaths, and the problem has emerged as a major source of discontent with China's government.
The noxious haze - a common phenomenon in winter in many parts of northern China - was once again a top topic on China's internet message boards.
Images of statues of Chinese intellectuals Li Dazhao, Cai Yuanpei and Chen Daisun, along with Spanish writer Miguel de Cervantes, wearing anti-pollution facemasks were among the most shared on Tuesday.
"This is a silent protest!", said one netizen on Sina Weibo, China's version of Twitter, under a picture of the statues at Peking University.
Levels of PM 2.5 have repeatedly reached more than 400 micrograms per cubic metre in recent days, according to a count by the US embassy in Beijing.
This figure is more than 16 times the World Health Organization's (WHO) safety guideline of 25 micrograms.
President Xi Jinping was pictured on Tuesday walking outdoors - without a facemask - in Nanluoguxiang, a popular restaurant district just south of Beijing's ancient Drum Tower.
But his stroll did not appear to be spontaneous, as television cameras were also in evidence in the pictures posted on Weibo.
