Residents of quarantined Chinese city Xian have been desperately bartering electronics for food amid worsening fears of shortages and star… Residents of quarantined Chinese city Xian have been desperately bartering electronics for food amid worsening fears of shortages and starvation. It comes as Yuzhou, a city of 1.2million in central China, was locked down on Tuesday after just three asymptomatic Covid-19 cases were recorded. Xian's 13 million residents have been confined to their homes since December 23 and are banned from leaving even for food and essential supplies, having to rely on local officials to drop off care packages. But…