(CNN) A Duke University professor who warned Chinese students against communicating in their native language and urged them to speak English instead has stepped down as the head of a master's program and apologized after her emails sparked outrage on campus and on social media.

Students are calling for a further investigation into the emails and claims that those speaking Chinese outside of class might not be given the same opportunities as other students.

In her message sent to students on Sunday, Megan Neely wrote: "I deeply regret the hurt my email has caused. It was not my intention. Moving forward, it is my sincerest wish that every student in the Master of Biostatistics program is successful in all of their endeavors."

Megan Neely has stepped down as the head of the Master of Biostatistics program at Duke University.

"Something to think about," read the subject line of an email Neely sent Friday. Neely, who headed the Master of Biostatistics program in the university's School of Medicine, sent the email to first and second-year students in the program. In it, she urged the students to "commit to using English 100% of the time" in a professional setting.

In the email, Neely said that she had been approached by two faculty members who complained about international students speaking Chinese in student lounge and study areas.

"They were disappointed that these students were not taking the opportunity to improve their English and were being so impolite as to have a conversation that not everyone on the floor could understand," Neely wrote in bold, underlined type. She said the faculty members asked to see photographs of the students in the program so that they could "remember them if the students ever interviewed for an internship or asked to work with them for a master's project."

One professor from Duke University sent out an email asking Chinese students not to speak Chinese in school building. pic.twitter.com/6xGkIeScJo — Hua Sirui 华思睿 (@siruihua) January 26, 2019

"To international students, PLEASE PLEASE PLEASE keep these unintended consequences in mind when you choose to speak Chinese in the building," Neely's email continued. "I have no idea how hard it has been and still is for you to come to the US and have to learn in a non-native language. As such, I have the upmost (sic) respect for what you are doing. That being said, I encourage you to commit to using English 100% of the time when you are in Hock or any other professional setting."

On Sunday, Neely apologized in a joint statement with the chair of the biostatistics department.

"We very much value our international students and their contributions to our program and we recognize that the message that was sent Friday was not appropriate," the statement said. "Although it was not meant to be hurtful, it came out that way and was clearly in error."

Neely sent a similar email last year

Neely sent a similar email to students in the Master of Biostatistics program in February 2018.

Okay there's another email sent in Feb 2018 https://t.co/gMtHESGrCy pic.twitter.com/kK6nidQAYY — Hua Sirui 华思睿 (@siruihua) January 26, 2019

In that email, Neely wrote that she had received reports from faculty that many international students were not speaking English in the department's break rooms. She said that she wanted to offer students advice on why that "might not be the best choice."

"Beyond the obvious opportunity to practice and perfect your English, speaking in your native language in the department may give faculty the impression that you are not trying to improve your English skills and that you are not taking this opportunity seriously," she wrote in the February 2018 email.

"Bottom line: Continuing this practice may make it harder for you and future international students to get research opportunities while in the program," the 2018 email continued.

Michael Schoenfeld, Duke's vice president for public affairs and government relations, confirmed the authenticity of both emails to CNN. CNN reached out to Neely for comment.

Though Neely has stepped down as director of the program, she will continue her role as an assistant professor of biostatistics and bioinformatics, Schoenfeld said.

'Absolutely no restriction or limitation on language,' dean says

Mary Klotman, dean of the university's School of Medicine, apologized for Neely's email in a letter to the program's students.

"I understand that many of you felt hurt and angered by this message," Klotman wrote. "To be clear: there is absolutely no restriction or limitation on the language you use to converse and communicate with each other. Your career opportunities and recommendations will not in any way be influenced by the language you use outside the classroom."

Klotman said she has asked the university's Office of Institutional Equity to conduct a review of the biostatistics program and recommend ways to improve the environment for students of all backgrounds.

"Please be assured that Duke University, the School of Medicine and the Biostatistics Department respect the value of every student, every culture and every language that is spoken," Klotman wrote.

Email is hypocritical and discriminatory, students say

A group of students started a petition calling for an investigation into the actions of the unnamed faculty in Neely's email. The students said it has more than 2,000 signatures so far.

The Duke Asian Students Association and the Duke International Association condemned Neely's emails and the actions of the unnamed faculty members in a joint statement

"This behavior is not only hypocritical -- given Duke's dependence on international students and faculty for their undergraduate and graduate programs, desire to present itself as a 'global university,' and partnership with Duke Kunshan University -- but also discriminatory," the statement read.

Many international students took offense to the implications in Neely's emails. They pointed out that speaking in another language isn't an indicator of one's proficiency in English.

"Speaking Chinese or other international languages, doesn't mean our English is not good," Evan Wang, who graduated from the biostatistics master's program in 2015, said. "It has nothing to do with our research skill set or the employment opportunities."

Xinyuan Zhang, a fourth-year doctoral student in electrical and computer engineering, said he understands that strong English skills are beneficial, but when he's speaking to other students from China like himself, it's easier to speak in his native language.

"For us, when we are in a studying environment or a working environment, we would prefer to use English, that's for sure. But in private conversations with only Chinese students, we would prefer Chinese," Zhang said.

He added that this wasn't just true for Chinese students, but that it was something he observed among Korean students, Russian students and others whose first language wasn't English.

Other students called for the university to look into the matter.

Michelle Li, a senior and president of the Asian Students Association at Duke, said she wants to know whether the problem extends beyond the biostatistics program.

"In the grand scheme of things, I want to know if this is one department or multiple departments," Li said. "It wasn't just one email, it was multiple emails. It wasn't just one director, it was multiple faculty involved."

The issues at the center of Neely's emails, students said, are also at the heart of a national conversation in the US.

"It kind of seems to tie into a national dialogue of who exactly is American and thus belongs here," said Li.

Trending in China

The email controversy has attracted great attention in China, drawing outrage on the country's Twitter-like social platform Weibo.

"If this isn't racist -- then what is?" wrote one user, highlighting a widely shared sentiment. "Why should these students' conversations be understood by others anyway?"

"If a Chinese university doesn't allow international students to speak English, or their native tongues, what would happen?" another user chimed in. "Being exclusionary in any form is a sign of barbarianism."

More than 363,000 Chinese students were enrolled in colleges and universities across the United States in the 2017-18 academic year, constituting the largest foreign student body, according to the Institute of International Education.

A US Commerce Department report in 2016 said Chinese students in the US contributed $9.8 billion to the American economy.