Security experts confirmed that China has just recently blocked the popular messaging app, WhatsApp, as a move to broaden online censorship.

During the past few months, WhatsApp went through few troubles to its service when the users were unable to send video chats or photos. Currently, the only left service of text messages was also blocked.

WhatsApp text message blocking shows that China’s censors might have generated specialized software for hindering with such messages that are dependent on an encryption technology used by some services other than WhatsApp, reported New York Times.

“Essentially, it seems that what we initially monitored as censorship of WhatsApp’s photo, video and voice note sharing capabilities in July has now evolved to what appears to be consistent text messaging blocking and throttling across China,” said Nadim Kobeissi, a cryptographer at Symbolic Software.

According to Kobeissi, China updated its firewall to identify and block the NoiseSocket protocol that is used by WhatsApp to send texts. WhatsApp already blocked the HTTPS/TLS that was used to send photos and videos. “I think it took time for the Chinese firewall to adapt to this new protocol so that it could also target text messages.” The app commotion started last Wednesday, The Verge reported.

This action can further blow off already long-banned Facebook, the owner of WhatsApp. With WhatsApp blocked and Instagram unavailable, the only feature left for Facebook in China is the Colorful Balloons app that was launched previous month.

Furthermore, irritated users also took to other social media sites to show their anger. A user commented, “Losing contacts with my clients, forced back to the age of telephone and email for work now.” Another one wrote, “Even WhatsApp is blocked now? I’m going to be out of business soon.”

However, WhatsApp refused to comment on this matter.