Nine Chinese students returning to school at Arizona State University were detained at Los Angeles International airport, denied entry into the country, and sent back home, just days before the start of classes.

Their detainment has sparked outrage and now ASU is demanding answers and pleading with Secretary of State Mike Pompeo to let the pupils back into the country.

The nine ASU undergraduates landed at LAX in the days prior to the start of classes on August 22, but their visas were 'deemed inadmissible' by Customs and Border Protection.

They were then detained by CBP officials 'over the last week', had their electronics searched, and were ultimately sent back to China, the university announced Friday.

All of the students were undergraduates. One was an engineering student, another studying supply-chain management, and several were life sciences majors. Some of those students were due to graduate this semester.

Nine Chinese students returning to school at Arizona State University were detained at Los Angeles International airport last month, denied entry into the country, and sent back home, just days before the start of classes. File image or a CBP officer above

The nine ASU undergraduates landed at LAX in the days prior to the start of classes on August 22, but their visas were 'deemed inadmissible' by Customs and Border Protection. LAX airport pictured above

University officials argue that the students were all academically eligible to return to ASU and the U.S. under their visas.

'We are working as quickly as possible to coordinate with the federal government to understand the circumstances surrounding these actions and to rectify the situation,' ASU said in a statement last week.

ASU said that it has not been given answers on why the students were detained and sent back.

The university clarified that the students were not detained due to any academic dishonesty issues.

'The Chinese students were deemed inadmissible to the United States based on information discovered during the CBP inspection,' CBP said to student paper the State Press in a statement.

According to CHP, there are more than 60 reasons why a foreigner would be considered in admissible including health-related grounds, criminality, security reasons and immigration violations.

CBP is yet to reply to DailyMail.com's request for comment.

However, they're still technically enrolled at the school working through ASU Online, a school official said. The university has been in contact with each of the students.

All of the students were undergraduates at Arizona State University (campus above). One was an engineering student, another studying supply-chain management, and several were life sciences majors. Some of those students were due to graduate this semester

In a letter addressed to Secretary of State Mike Pompeo and acting Secretary of Homeland Security Kevin McAllenan, school officials are asking for clarity on the matter and a review detainment procedures.

The letter reveals that the students were not only forced to return home, but they were ordered to pay for their own ticket or be banned from re-entering the country.

'In each case, the students were in possession of all needed documentation to enter the U.S. yet they were refused entry at the airport, told they needed to return to China, that they needed to pay for their own airline ticket to do so or face a ban from re-entering the U.S. for five years,' the letter, signed by University President Michael M. Crow, said.

The letter also asked for a review of airport detainment procedures that now include searching the electronic devices of students entering the U.S.

'It is beyond my comprehension how the U.S. government could establish and implement policies that bring about the outcomes we are now witnessing,' the letter said.

An official said Wednesday that Crow is yet to receive a response.

University President Michael M. Crow is demanding answers and sent this letter to Secretary of State Mike Pompeo and the Office of the Homeland Security asking for the reason behind the deportation and a review of protocol

The visa revocation comes after a Palestinian student living in Lebanon, who was an incoming Harvard University freshman, was denied entry into the country at Boston's Logan airport and sent back home on August 23.

The student, Ismail Ajjawi, 17, told school paper the Harvard Crimson he was detained for five hours, had his electronics searched, and was questioned about his friends' social media activity where they expressed anti U.S. views. He was also asked about his religion.

Ajjawi was finally admitted into the U.S. on Monday just in time for the start of classes after he 'overcame all grounds of inadmissibility', according to a CBP spokesperson.

Incoming Harvard University freshman Ismail B. Ajjawi, a 17-year-old Palestinian refugee, center, living in Lebanon, had his visa revoked hours after landing in the U.S. two weeks ago but he has now been allowed into the country. He is pictured on campus at Harvard on Monday

Customs and Border Protection said it could not release specific information about individual travelers because of privacy act requirements and law enforcement purposes as to why Ajjawi's visa was initially revoked

International students from China are increasingly finding themselves caught in Trump's trade war with China.

Campuses from several California schools have encountered visa delays, federal scrutiny over research projects, and restrictions on collaboration with China and Chinese companies, according to the Los Angeles Times.

ASU boasts about 13,000 international students, about 3,400 of which come from China.