The three men, of which two were swedish citizens, had checked in and gone through the security check, boarded the airplane and then "acted in a nervous manner", whatever that means.
All three had bought their tickets the day before departure.
The Captain then questioned the men as to why their had bought their tickets that late and if their knew each other. The police was called and they checked the men again. Finding nothing suspicious.
The Captain then elected to offload the three men.