A group of 24 Thais were denied entry to Korea after they made unsuccessful bid to explain the purpose of their stay in Korea, Newsis said Saturday.

It was rare for such many number of people in the same plane were denied entry, airport officials said, according to the news outlet.

The Thais flew in to Cheongju on Wednesday from Bangkok. It was the first flight since the Korean Airlines opened the new route.

According to police, the airplane carried 79 Thais and two South Koreans. Upon their arrival, the officials of the airport, located in the central part of the nation, discovered that the 24 individuals, including three females, said they would “take soccer lessons” at a training camp in Kyeonggi province.

All dressed in soccer uniforms, they said they would get a two-week training and go back to their country where they would serve as soccer teachers.

But customs officials found out that some of them didn’t have any rudimentary knowledge about soccer.

They went through further in-depth interviews during which they apparently failed to convince the officials.

The nation has stepped up efforts to screen illegal entry ahead of the G20 meetings in November.