The 23 students from a language course at the Christian Hanshin University were packed onto a bus and had their cell phones confiscated on Nov 27, according to Seoul’s Yonhap news agency.

It was only during the ride that the students were told they were en route to Incheon International Airport and that they must return to their country due to a “failure to meet the conditions to stay”, the report added.

Twenty-two students flew to Uzbekistan that day, while one remained due to health issues, according to Yonhap.

An official from South Korea’s Osan police station told AFP that the case “has been allocated to our criminal department”, without giving further details.

Hanshin University said the students had failed to meet their visa requirement of maintaining a minimum bank balance of 10 million won for at least three months.

The institution said despite repeated warnings, the students did not take action.

A spokesman told AFP that the university had been trying “to make arrangements for the students to have the opportunity to leave the country and return to South Korea without any change in their (legal) status”.

According to South Korean daily The Hankyoreh, the students were initially deceived and boarded the bus thinking they were going to the “immigration office to collect their alien registration cards”.

Legal experts told AFP that universities do not have the authority to deport international students.

In normal circumstances, “the immigration office should recommend or notify them to leave the country and allow them to return home on their own once their visa expires,” Cho Young-kwan, a lawyer and activist at Migrants Center Friend told AFP.

Lawyer Kim Ji-rim said the university “effectively incarcerated” the students and gave them false information, which amounts to criminal intimidation.