Beijing -- China on Tuesday questioned the appropriateness of an email sent by a Duke University medical school administrator warning Chinese students to speak in English. Asked about the controversy, foreign ministry spokesman Geng Shuang compared it to a Chinese university demanding that English-speaking students talk only in Chinese.

"If a Chinese university required that American students not use English to communicate, I think this would not be normal," Geng said at a daily briefing.

Duke University in North Carolina moved quickly to offer apologies, launch an investigation and reassure a core group of graduate scholars after the email raised an outcry at home and abroad.

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The story drew thousands of comments in China on social media. Some called it racial discrimination and said Chinese universities should ban speaking English, while a few said it was not a big deal.

The administrator's message came at a time when elite U.S. universities are trying to remain attractive to top international students despite negative rhetoric toward foreigners by President Donald Trump and other politicians.

Protests mounted after the email was sent Friday by Megan Neely, who teaches in the biostatistics master's degree program and served as its director of graduate studies.

Neely's message to an email list for about 50 biostatistics students said two faculty members approached her to complain about students speaking loudly in Chinese in a common area. She wrote that both were disappointed the students weren't working to improve their English and wanted their names. The email urged international students to "keep these unintended consequences in mind when you choose to speak in Chinese in the building."

Amid the angry response, Neely stepped down as the program's director of graduate studies, according to a letter from Mary Klotman, the medical school dean.

Klotman apologized to students in the program in her letter, saying there was no restriction on using foreign languages in conversations.

Neely, who remains an assistant professor, apologized in an email to program members, saying: "I deeply regret the hurt my email has caused. It was not my intention."