One of the worst affected was Tianjin where authorities grounded dozens of flights and closed most highways after severe smog blanketed the port and industrial city.
Smog – the scourge of winters in China – affected dozens of cities on Sunday with more than 40 in the country’s North-east issuing pollution warnings.
One of the worst affected was Tianjin where authorities grounded dozens of flights and closed most highways after severe smog blanketed the port and industrial city.
Air quality index readings at some monitoring stations in Tianjin peaked above 400, state-run news agency Xinhua said. Anything above 300 is considered hazardous by the US Environmental Protection Agency.
Beijing activated its first red alert for smog this winter as the air began to turn hazy at the weekend.
China's environmental watchdog has issued a five-day warning and ordered factories to shut; recommended residents stay indoors and curbed traffic and construction work.