China’s leaders expanded a mass roundup of people possibly sickened with the coronavirus on Thursday, widening their dragnet well beyond the epicenter of the outbreak to at least two more cities in what the government has called a “wartime” campaign to stamp out the epidemic.

But the campaign, first announced last week in the city of Wuhan, already has been marred by chaotic conditions that have isolated vulnerable patients without adequate care and, in some cases, left them alone to die.

The expansion of the decree to “round up everyone who should be rounded up” in the Wuhan area of central China has deepened the nation’s sense of anxiety.

In their zeal to execute the edict, officials in Wuhan, a metropolis of 11 million, have haphazardly seized patients who have not yet tested positive for the coronavirus, in some cases herding them onto buses with no protective measures where they risked infection from others, their relatives said.