Aerials of empty streets in Xi'an amid lockdown

China on Thursday redoubled efforts to control new virus outbreaks with a lockdown of the 13 million residents in the northern city of Xi'an, following a spike in coronavirus cases.

The measure comes just weeks before the country hosts the Winter Olympics in Beijing, roughly 1,000 kilometers to the northeast. There was no word on whether the virus was the newly surging omicron variant or the far more common delta strain.  China has reported just seven omicron cases.