Heavy smog in large parts of China has caused over 150 flights to be cancelled and highways to shut after the New Year holiday. Beijing Traffic Management Bureau said, dense fog also temporarily closed several sections of six expressways in Beijing yesterday.<br/><br/>The smog covering Beijing and 71 cities for the past five days is set to get worse in the next few days. China's national observatory has issued a red alert for fog and renewed an orange alert for smog in a number of northern, eastern and central regions.<br/><br/>The Ministry of Environmental Protection said, its rectification measures have not yet been fully implemented, and some enterprises in cities severely affected by smog have performed poorly in emissions reduction evaluations. Government has dispatched 40,000 officials to inspect violations by factories flaunting warnings to halt operations.