BEIJING, March 27 -- The National Meteorological Center (NMC) on Friday issued a blue alert for sandstorms that will choke north China in the coming days.

The NMC forecast that dusty weather will sweep north China from Friday to Saturday, bringing strong winds and floating dust to Xinjiang, Inner Mongolia, Gansu, Ningxia and Shaanxi. Some regions will even see sandstorms.

It is the fourth time this year for sandstorms to hit the country's northern regions, double the number seen during the same period last year, the NMC added.

The weather observatory advised residents to stay indoors and asked local authorities to brace for the weather.

China has a four-tier color-coded weather warning system, with red representing the most severe weather, followed by orange, yellow and blue.