Tangshan city in Hebei province made provisions recently for flexible working hours and for buses to offer free rides when the city was hit by heavy pollution, Xinhua News Agency reported on Tuesday.

The city's government issued a document stipulating that when heavy pollution occurs, primary and middle schools and kindergartens will be closed, and enterprises will implement flexible working hours.

Also, urban buses will not charge fares and those enterprises which produce pollution, such as cement works and steel factories, will stop production.