Airplanes wait in fog at the Beijing Capital International Airport in Beijing, capital of China, Feb. 17, 2013. (Xinhua/Ma Ruzhuang)Related:Smog disrupts Beijing traffic, flightsBEIJING, Feb.17. Photos: Xinhua
Buildings are shrouded in fog in Beijing, capital of China, Feb. 17, 2013.
Buildings are shrouded at the Beijing Capital International Airport in Beijing, capital of China, Feb. 17, 2013.
Vehicles run on fog-shrouded road in Yongqing County of Langfang City, North China's Hebei Province, Feb. 17, 2013.
Vehicles run on fog-shrouded road in Qinhuangdao City, North China's Hebei Province, Feb. 17, 2013.
A citizen wearing face mask walk in fog in Liaocheng City, East China's Shandong Province, Feb. 17, 2013.
A woman ride in fog in Neihuang County of Anyang City, Central China's Henan Province, Feb. 17, 2013.
The city is seen through the fog in Nanning, capital of South China's Guangxi Zhuang Autonomous Region, Feb. 17, 2013. Heavy fog engulfed Nanning here on Sunday.
Buildings are shrouded in fog in Nanning, capital of South China's Guangxi Zhuang Autonomous Region, Feb. 17, 2013.
The city is seen through the fog in Nanning, capital of South China's Guangxi Zhuang Autonomous Region, Feb. 17, 2013. Heavy fog engulfed Nanning here on Sunday.
The city is seen through the fog in Nanning, capital of South China's Guangxi Zhuang Autonomous Region, Feb. 17, 2013. Heavy fog engulfed Nanning here on Sunday.
Combo photo shows citizens wearing face masks in fog-shrouded Yinchuan, capital of Northwest China's Ningxia Hui Autonomous Region, Feb. 17, 2013.
Buildings are shrouded in fog in Yinchuan, capital of Northwest China's Ningxia Hui Autonomous Region, Feb. 17, 2013.