Image-curation website Pinterest has become the latest social media service blocked in China, checks on censorship monitoring websites indicated Friday.
According to greatfire.org and blockedinchina.net, the popular virtual bulletin board service has been unavailable in mainland China since last Thursday.
The San Francisco-headquartered service joins rival photo-sharing firm Instagram -- which has a much larger user base -- as well as Twitter and Facebook on the list of social media platforms inaccessible in mainland China.
The ruling Communist party restricts access to many foreign websites including Google, with a vast network of controls dubbed the Great Firewall of China.
While China user numbers are not available, Pinterest is a hit particularly among women, who tend to pin images about non-political subjects such as food, fashion and travel.
However, some Pinterest users maintain public boards on subjects that are deemed politically sensitive in China -- such as human rights issues.
There is a Pinterest board devoted to jailed dissident Liu Xiaobo, for example, and another on the Senkakus, an archipelago controlled by Japan, which China claims as the Diaoyus.
"It will be very hard to do my homework later because I had collected the works of a designer there," a student wrote on Weibo, China's native version of Twitter.
Another Weibo user, who described herself as an e-commerce designer, wrote that Pinterest was a key tool in her job and it will be "hard to work effectively without it".
A 2015 report by US think tank Freedom House found that China had the most restrictive Internet policies of 65 countries it studied, ranking below Iran and Syria.
China is home to the world's largest number of internet users -- 731 million as of December -- the government-linked China Internet Network Information Center said in January.