Chinese technology giant Tencent Monday apologized for a "technical error" of its new WeChat feature that allows the US flag to flood users' mobile screens by typing key words, after being questioned by some Chinese officials.

The apology came after the local committee of the Communist Youth League in Fujian Province said on its Sina Weibo Sunday that WeChat offered no such features when typing "National Day" or "China" but icons of the US flag could appear on the screen after typing "civil rights."

The WeChat team said in a statement that their branch office in the US launched the new feature to honor Martin Luther King Jr., as every Monday of the third week in January marks Martin Luther King Jr. Day.

"The feature was supposed to be only available for users in the US. However, it was opened for some other users due to a mistake in the settings. We apologize for the misunderstanding caused by the error," read the statement.

Chinese mobile users on Sunday were surprised to see icons of the US flag flying down their app screens when typing "civil rights" in conversations.

The post quickly triggered heated discussions among Net users and has attracted 2,973 comments and 6,980 reposts as of press time. Some netizens accused the company of catering to the US.

"The concerns among the Chinese will damage the company's image in the domestic market. It may have reflected   the company's preference for the international market as it is going global," said Qin An, a cyber security expert at the China Institute for Innovation and Development Strategy.