China locks down city of 4m people after six Covid cases detected

Residents in Lanzhou, Gansu, told to stay at home as buses, taxis and key rail routes suspended

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China has placed a city of 4 million under lockdown in an attempt to stamp out a domestic coronavirus outbreak, with residents told not to leave home except in emergencies.

Beijing imposed strict border controls in the weeks after Covid-19 was first detected in China in late 2019, slowing the number of cases to a trickle and allowing the economy to bounce back.