Dec. 26 (UPI) -- Taiwan authorities believe 152 Vietnamese tourists who went missing from their tour groups last weekend may be involved in human trafficking.
The country's National Immigration Agency has started a manhunt in hopes of finding the tourists, Taiwan News reported.
ETholiday, the agency managing the tour groups, reported the tourists arrived for a stay from Friday to Sunday, but all but one disappeared. The tourism bureau said it's informed the Consular Affairs Bureau that it canceled the visas of the missing tourists and voided the applications of 182 others scheduled to visit.
The tour agency said when the groups arrived at Kaohsiung International Airport, they were picked up by people not affiliated with the group.
The immigration agency said it believes the plot to leave the airport must have been preplanned in Vietnam.
The state-run Central News Agency in Taipei reported Wednesday that eight international students connected with a Taiwan program meant to attract overseas students have also gone missing.
Some students who go to Taiwan for the program never attend school, but rather take jobs to live there. If they become unaccounted for, it can lead to their arrest and deportation.
Immigration officials said they fear missing Vietnamese male tourists could end up working illegally in factories with the women becoming involved in the sex trade.