Japan may ban a North Korean ferry suspected of involvement in illicit activities from carrying passengers if inspections during a scheduled port call Monday determine it violates safety standards for lifeboats, sources close to the case said Saturday.

If the Man Gyong Bong-92 fails to provide high-speed lifeboats, as required under an international treaty, the Land, Infrastructure and Transport Ministry will be able to issue such an order, the sources said.

In that event, the cargo-passenger ship would only be allowed to carry cargo when it leaves Niigata port for Wonsan, eastern North Korea, leaving behind some 260 people. Most of those passengers are students of pro-Pyongyang Korean ethnic schools scheduled to take part in school excursions, they said.

In a related move, a school in Toyoake, Aichi Prefecture, has decided to put off a two-week trip for 110 third-year high school students that was to start Tuesday and use the ship, school officials said.