SHIJIAZHUANG -?The local government of Shijiazhuang, capital of north China's Hebei Province, has apologized to the public for inconvenience caused by the city's anti-smog measures.

In an open letter issued Friday, the government expressed its "sincere apology" to its citizens, adding that it hopes to have the understanding and cooperation of the public for a series of urgent measures it has taken amid acrid smog, particularly the odd-even license plate restrictions for driving cars.

The city government said it faces a daunting task to clean up its foul air, adding that pollution has been severe since late September. It also explained the reasons behind the pollution, namely burning coal, construction in downtown areas and car emissions. Under unfavorable weather conditions, smog is inevitable, it said.

"Out of concern for the health of the public, we decided to take the strictest anti-smog measures after careful consideration," read the letter. "These measures will inevitably cause some inconvenience, especially the odd-even car restriction."

Shijiazhuang has been haunted by smog over the past few days, with authorities on Tuesday issuing an orange alert, the second most severe in a four-tier color-coded system.

On Thursday night, it issued a notice demanding all car owners follow the odd-even car restriction until the end of the year. Previously it issued different restriction policies on Nov. 8, Nov. 10, Nov. 11 and Nov. 15.