China's bid to contain a deadly new virus by placing cities of millions under quarantine is an unprecedented undertaking but it is unlikely to stop the disease spreading, experts warn.
The contagious virus has already reached elsewhere in
China and abroad, and even an authoritarian government has only a small timeframe in which trapped residents will submit to such a lockdown, they say.
"I think we have passed the golden period of control and prevention," said Guan Yi, an expert on viruses at Hong Kong University.