China has told South Korea that it has blocked online services of South Korea's two popular mobile messaging applications, KakaoTalk and Line, since earlier this month, a South Korean diplomat with the knowledge of the matter said Monday, adding that the services would "soon" return to normal.

Along with other foreign online services, including Yahoo Inc.'s photo-sharing site Flickr, users in China have been unable to access online services of KakaoTalk and Line for more than 10 days.

Some anti-censorship activists say the new blockages could apparently be an attempt by Chinese authorities to block information in the wake of the 25th anniversary of the Chinese Communist Party's brutal crackdown on pro-democracy demonstrations at Beijing's Tiananmen Square.

The South Korean diplomat, who spoke on the condition of anonymity because of the sensitivity of the issue, said the Chinese authorities informed the South Korean government of "blockages of foreign online messaging apps, including KakaoTalk and Line."

"The Chinese side tells us that the blockages will not last for a long time, and I expect services to return to normal by the end of this month," the envoy at the South Korean Embassy in Beijing said.

Asked why the Chinese authorities blocked such apps, the diplomat replied, "The Chinese side also gave a brief reason for that, but I can't talk about the reason."

The Chinese authorities have kept a tight control on the Internet. Most services of Google, the world's biggest search engine, and the entire services of Facebook and Twitter have been blocked in China. (Yonhap)