TIANJIN, March 24 (Xinhua) -- North China's Tianjin Municipality issued a yellow alert for air pollution on Saturday, forecasting heavy air pollution from Sunday until Wednesday.

The yellow alert warns of an Air Quality Index (AQI) of more than 200 micrograms of harmful fine particulate matter per cubic meter of air for two consecutive days.

Emergency response measures, including limiting emissions from enterprises and suspending construction work, will be activated starting at 12:00 a.m. Sunday.

The AQI reading in some parts of the city topped 300 on Saturday morning, according to the city's environmental monitoring center.