12/06/2013 02:51 EST | Updated 02/04/2014 05:59 EST

Pollution in Shanghai spikes to extremely hazardous levels, obscures skyline, curbs city life

SHANGHAI - Shanghai authorities have ordered youth indoors and halted construction as China's financial hub suffers one of its worst bouts of air pollution, bringing visibility down to a few dozen meters and obscuring its spectacular skyline.

Authorities say the city's concentration of tiny, harmful PM 2.5 particles was 602.5 micrograms per cubic meter early Friday afternoon, an extremely hazardous level. That compares with the World Health Organization's safety guideline of 25 micrograms.

Experts blame Shanghai's pollution on coal emissions in the region combined with weather patterns that have left the city's air stagnant.