(Bloomberg) -- WhatsApp has begun working freely and consistently for some users in China despite a longstanding government ban on the messaging service, an unusual phenomenon for a country with some of the world’s strictest internet curbs.

Users of the Meta Platforms Inc. service in Beijing and Shanghai, who normally employ workarounds like a virtual private network to get on the service, have been sending and receiving messages without those tools. Other social media services such as Signal and Instagram remain barred, part of a broad blockade of foreign internet platforms that critics have dubbed the Great Firewall. 

It’s unclear how many people across China have been able to navigate WhatsApp during the period. The phenomenon hasn’t yet trended on domestic social media such as the Twitter-like Weibo. Only several million people are estimated to use Meta’s signature messaging tool in the country, versus more than a billion for Tencent Holdings Ltd.’s WeChat. Representatives for WhatsApp declined to comment, while the Cyberspace Administration of China didn’t respond to a faxed query.

Read More: Apple Pulls WhatsApp From China Store at Beijing’s Behest

Beijing has barred the use of foreign messaging and social media platforms like WhatsApp for years, part of a broader campaign to tamp down potential dissent and enforce the Party’s control of content. That’s helped apps like WeChat and Weibo dominate, though Chinese users still employ VPNs to view Western media. Like most foreign messaging platforms, WhatsApp messages are encrypted on both ends and are difficult to police.

Still, users in China have in the past reported being able to access blocked services and websites for brief periods, which industry experts attribute to glitches in network restrictions. But at least some people in China’s two largest cities say they’ve been able to send and receive WhatsApp messages over an uninterrupted two-week span — an unusually long period for the country.

At least one of the users said that span began right around the time Apple Inc. removed WhatsApp and other social media services including Threads and Signal from its Chinese app store, responding to orders from Beijing to close more loopholes in the internet firewall.

--With assistance from Kurt Wagner.

©2024 Bloomberg L.P.