Beijing on pollution 'red alert', but smog not as severe as forecast

An aerial view shows smoke billowing from chimneys of factories located near Beijing, amid heavy smog under a red alert for air pollution, China, December 19, 2015. REUTERS/Stringer

BEIJING (Reuters) - China's capital Beijing was bracing for four days of choking smog starting on Saturday, but residents said the haze was less severe than forecast, with some questioning why the government had issued its highest air pollution alert.

China had warned residents across a large part of its north on Friday to prepare for severe smog arriving over the weekend, the worst of which would hit Beijing, prompting the capital to issue its second ever "red alert".