A Ferris wheel is seen through smog in Tianjin Municipality, north China, Feb 23, 2014. China's top meteorological authority, National Meteorological Center (NMC), on Sunday continued to warn of smoggy weather that has battered parts of China for days. Smog will persist from Sunday morning till Monday morning in Beijing and Tianjin municipalities, as well as parts of Hebei, Shandong, Henan, Shanxi and Shaanxi provinces, the NMC said. (Xinhua/Zhang Chenlin)

Citizens walk in smog in Tianjin Municipality, north China, Feb 23, 2014. China's top meteorological authority, National Meteorological Center (NMC), on Sunday continued to warn of smoggy weather that has battered parts of China for days. Smog will persist from Sunday morning till Monday morning in Beijing and Tianjin municipalities, as well as parts of Hebei, Shandong, Henan, Shanxi and Shaanxi provinces, the NMC said. (Xinhua/Zhang Chenlin)