TAIPEI, Taiwan (AP) — Angry bank customers who traveled to a city in central China to retrieve their savings from troubled rural banks have been stopped by a health app on their cellphone.

Chinese residents are required to have the health app, which displays a code indicating their health status, including possible exposure to COVID-19. A green code is required to use public transportation and to enter locations such as offices, restaurants and malls. But some depositors at the banks in central Henan province said their codes were turned red to stop them.

The incident has started a national debate on how a tool designed for public health was appropriated by political forces to tamp down controversy.

The issue started in April, when customers found they could not access online banking services. They tried to report the banks and get their money back, but didn’t get replies.

Thousands of people who had opened accounts with the six rural banks in Henan and Anhui provinces began trying to withdraw their savings after media reports that the head of the banks’ parent company was on the run. The majority shareholder of several of the banks, Sun Zhenfu, was wanted by authorities for “serious financial crimes,” according to the official media outlet The Paper.

Authorities likely feared a bank run, which is not uncommon with smaller banks in China that tend to be less stable than their larger, institutional counterparts.

Customers from around the country were connected with the rural banks through financial platforms such as JD Digits. There, the small banks sold customers financial products such as fixed deposit accounts with higher interest rates, which require people to deposit their money for a set amount of time, according to Sixth Tone, the sister publication of The Paper.

Unable to resolve the issue online, customers set out earlier this week to demand government action at the Henan province office of the China Banking and Insurance Regulatory Commission in the provincial capital, Zhengzhou. But after arriving in the city, they found they couldn’t go far.

In one since-deleted account on the social media app WeChat, a woman surnamed Ai said shortly after she checked into a hotel in Zhengzhou, she was questioned by a group of police who asked her why she was there. She replied that she wished to withdraw money from the bank. Shortly after, she found her health code had turned red even though she had a negative COVID-19 test result in the previous 48 hours.

She was immediately taken to a quarantine hotel by a pandemic prevention worker.

Sixth Tone interviewed over a dozen people who said their health codes turned red after they scanned a QR code in the city.

In China, places like train stations and grocery stores have QR codes to scan at their entrances, logging people’s presence for contact tracing during the pandemic. When people are deemed to be at risk for COVID-19, their codes are turned different colors that indicate restrictions such as mandatory quarantines.

With a red health code, it’s impossible to go to any public venues, or even to board a train.

One bank customer, who gave her last name as Liu, said she saw that many people were reporting their health codes had turned red after arriving in Zhengzhou.

Liu, who did not go to Zhengzhou herself, said she tested the code change after others reported it in their shared group chat. After scanning the QR code from a photo someone had shared in the group, Liu found that her health code also turned red.

Another bank customer told Sixth Tone that he got a red code after scanning in at the train station in Zhengzhou and was taken into police custody. A few hours after police officers made him leave Zhengzhou, his health code turned green.

Jiakedao, a social media account run by the main Communist Party newspaper, criticized the Henan authorities in an editorial on Tuesday.

“Let’s be frank, no matter which department or individual instigated it, arbitrarily using the epidemic prevention and control measures for ‘social governance’ or ‘stability maintenance’ should be strictly held accountable,” the editorial said.

An official with Henan’s Pandemic Control Committee said in response to Jiakedao that authorities were investigating the reports of health codes being turned red.

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