Chinese authorities also appear to have stopped users sending photos and voice messages.
Asia business reporter
Users of the encrypted messaging service WhatsApp have raised concerns over censorship after disruptions in China.
The disruptions started over the weekend, when users noticed that WhatsApp wouldn't send pictures, voice messages and video unless they used a Virtual Private Network to get around China's censorship filters.
For some users the service appeared to be back to normal early on Wednesday, before more disruptions later in the day.
The Chinese government hasn't said if it's trying to censor the service, but nor has WhatsApp suggested its a technical problem.
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