Narita International Airport allowed 159 people who arrived Sunday on a flight from Taiwan to enter Japan without going through immigration because of a logistics mishap.

Japanese budget carrier Vanilla Air said Monday that around 110 of the passengers on Flight 104 from Taipei to Tokyo have already been contacted and processed properly, and that the remainder are being contacted by phone or email.

"We have not heard of an incident before in which this many people entered the country (through Narita) without going through immigration," an official from the airport's operator said.

The mistake occurred when the buses transporting the passengers to the terminal dropped them off at an arrival gate for domestic flights.

It is possible Flight 104 was mistaken for a domestic flight because it was temporarily diverted to another airport in Aichi Prefecture before arriving at Narita due to strong winds, Vanilla Air said.

Most of the people Vanilla Air is still trying to reach are Japanese, the carrier said.