BEIJING -- Officials in the northwestern Chinese city of Xi'an are facing punishment after a COVID-19 outbreak led to the lockdown of its 13 million residents, authorities said on Friday, as the number of new cases declined.

All domestic flights out of Xi'an and most trains originating from the city scheduled for Friday were canceled.

Officials in Xi'an, which is famed for its terracotta warriors buried with China's first emperor, say the outbreak has been traced to the arrival of a plane from Pakistan.

The Central Commission for Discipline Inspection said in a statement that 26 people in Xi'an were being held accountable for "not doing a good job" in their COVID-19 prevention and control effort, but did not specify their punishment.

New locally transmitted cases with confirmed symptoms in the city fell to 49 for Dec. 23, down from 63 a day earlier, the first decline since Dec. 10.

Since Thursday, each Xi'an household has been limited to sending only one person to shop for necessities every two days, while others may not leave unless they have essential jobs.

Xi'an has launched multiple rounds of mass testing.

TOUGH MEASURES

While the number of local symptomatic cases in Xi'an - there were 255 during the Dec 9-Dec 23 period - and in China overall is tiny compared with outbreaks elsewhere, authorities have used heavy-handed measures that have for the most part succeeded at preventing localized outbreaks from spreading.

China is especially determined to extinguish any outbreak as Beijing prepares to stage the Winter Olympics in February

The country has all but shut its borders to international arrivals, and those coming for the Games will be sequestered inside a strictly-enforced "closed-loop."

China's aggressive COVID-fighting approach has crimped domestic travel and consumer spending, and caused occasional localized industrial disruptions.

On Friday electric vehicle maker BYD Co was seeing "some impact" from the lockdown on its operations in Xi'an, a company representative said.

Nationwide, China confirmed 87 new symptomatic cases for Dec. 23, down from 100 a day earlier, its health authority said on Friday.

Of those, 55 were locally transmitted, according to a statement by the National Health Commission, compared with 71 from a day earlier.

There were no new deaths, leaving the death toll at 4,636. Mainland China had 100,731 confirmed COVID-19 cases as of Dec. 23.