Facebook-owned social media messenger WhatsApp, which was temporarily blocked in China earlier this year, has once again come under the scrutiny of the ruling communist party.

Many users, particularly in mainland China, are facing difficulty in using WhatsApp, while others are able to use only the text-based messaging feature, the New York Times reported.

Back in June, the Chinese government had reportedly set up filters and firewall to block WhatsApp's key features like image and video sharing to discourage citizens from indulging in badmouthing the government decision to not to provide proper medical care to Liu Xiaobo, a political prisoner due to his pro-democracy views.

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Sadly, Xiaobo, who was diagnosed with liver cancer, died of multiple organ failure at a closely guarded hospital on July 13, making him the first Nobel peace prize winner to die in confinement since German pacifist Carl von Ossietzky. The 1935 recipient had died under custody after several years of captivity in Nazi concentration camps.

[Representational image]Creative Commons

Soon after Xiaobo's death, the Chinese government lifted the restriction on WhatsApp, but the recent blockade is said to be related to the upcoming 19th National Congress of the Communist Party of China.

The 19th National Congress of the Communist Party of China, which is scheduled on October 18, will be attended by top party delegates to decide on a new leadership of the party, including the Central Committee and alternate members of the Central Commission for Discipline Inspection.

The party is anticipated that liberal citizens might make use of WhatsApp's encrypted messaging service to spread anti-government propaganda through videos, graphic images and text quotes and possibly attempt to disrupt the event. 

If history is any indication, China is expected to revoke the WhatsApp blockade once the 19th National Congress of the Communist Party of China concludes in October-end.

This is a developing story. Stay tuned. Follow us @IBTimesIN_Tech on Twitter for latest updates on WhatsApp blockade in China.