Sudden gales brought sand and dust back to Beijing yesterday, darkening the bright hopes of improving air quality in the capital after efforts to tackle pollution for last year's Olympic Games.
Strong north winds began to lash the city from mid-morning.
By the afternoon, the skies had turned yellow, although some sunlight still filtered through the sand and dust.
Backs bent and eyes squinting, people hurried along the streets of the capital, the men with their collars pulled tight around their necks, and the women with their heads wrapped in scarves.
The stinging sand drove most people indoors, but athletes taking part in the International Marathon Contest and the marathon programme for the 11th National Games still managed to hit the finish line - with their mouths clamped.
But according to Beijing meteorological authorities, there was no dust storm, only wafting sand that appeared in some parts of the city. It reported an air-quality index of 92 yesterday - 'relatively fine', and good for training and exercise.
'According our monitor of the weather ... there is no dust storm occurring,' a weather forecaster with the Beijing Meteorological Bureau said. He declined to give his name. He said the gale yesterday would temper into a breeze today, without any threat of a large-scale dust storm.
The China Meteorological Administration, the national weather forecaster, said a strong cold front was sweeping across northern China from the west, causing a temperature drop of 6 to 10 degrees Celsius.
It forecast that the dusty weather would arrive in the central and eastern parts of Inner Mongolia, north of Beijing, by tonight.
Xinhua suggested that the sand and dust could have originated from Inner Mongolia.
Pointing to a record number of days of air quality at or above the level of 'relatively fine', the municipal government has said Beijing's air was at its best in the past decade.