North China's Tianjin Municipality issued an orange alert for air pollution Wednesday.
An orange alert, the second highest in the city's four-tier warning system, indicates a predicted air quality index (AQI) over 200 for three consecutive days.
From Thursday, manufactures in the city will be ordered to cut emissions by at least 50 percent and fireworks will be prohibited. An odd-even number plate rule will restrict trucks on the roads.
Children, the elderly and infirm are advised to stay indoors.
