Beijing - Prohibited from passing cars and factories asked to shut down in Beijing on Saturday, December 19, 2015. This was done after the city was once again shrouded in smog dangerous.
The government issued a hazard alert level four, or a four-level warning system is the most serious.
This is the second warning issued in the last few weeks. It means making a lot of schools and half of that is forbidden to the vehicle.
Smog wave is expected to cover the full famous city's most polluting until the next Tuesday, December 21, 2015 since the presence of strong winds, as reported by the BBC on Saturday, December 19, 2015.
PM2,5 level, or the smallest particles of smog and the most deadly, soared to 303 micrograms per cubic meter in some areas in Beijing on Saturday. The possibility could be increased up to 500 in a few days - or more than 20 times the level considered safe by the World Health Organization (WHO).
Beijing Municipal Environmental Monitoring Center said overall air quality is 104.
Some residents reported on Weibo - or the Chinese version of Twitter - that is not as heavy smog that has been warned to them and complained about the ban on driving.
The Chinese Government has been criticized for not immediately issue a hazard warning smoke more often. This four-level warning system had been issued two years ago, but only this month Beijing finally announced it.
Despite, many people feel the government is now much better.
"In the past, the government did not issue any warning, even though the smoke was so thick," said one resident named Ma Yunan.
"Now, they have released a warning well in advance so that we are prepared. Not only that, they also have to do something to overcome," he added.
Smoke pollution in Beijing are mostly from coal-fired power plants, industrial smoke and the number of cars. In addition, the city's geographic aggravate the smoke being surrounded by mountains.
China is the world's largest carbon emitters. Although the world climate conference in Paris ago, they promised to reduce by 50 percent within the next five years. However, experts argue, China's emissions will rise in 2030 before eventually expected to decline.
