The University of the Chinese Academy of Sciences has launched a formal investigation after one of its students allegedly posted slurs on a foreign social media platform, the university said on Saturday.

The investigation team has found the offensive words were posted by a second-year graduate student surnamed Ji, the university said via a Weibo post.

His words run against the university's values and seriously harmed the feelings of Chinese people, the university said, adding the student has deleted the posts and issued an apology on the platform.

The university will further look into and seriously deal with the incident according to school regulations, it said.

In now deleted Twitter posts which can be seen in online screenshots, Ji used "Shina pigs", "Shina losers" and "Shina basebred animals" to refer to Chinese netizens. "Shina" is a racially charged derogative term toward China and Chinese people.

According to the apology letter posted on Twitter on Saturday, the student said he feels deep sorrow and regret for his behavior.

"As a Chinese citizen, my behavior has harmed my motherland and I have let down my parents and teachers," he said. "I have realized the seriousness of my behavior and I fully accept criticism from netizens. I will continue to seriously reflect on my behavior."