The woman, who recently got married, told her family that she would travel to Turkey to be with her husband, but several friends believed she would try to cross the border into Syria to join ISIL, and warned the police, the Swedish GT newspaper reported.
Police now reportedly believe that the Norwegian woman may married an Islamic State fighter and and plans to carry out a suicide attack.
According to the newspaper, Norwegian police have “no idea” where the terrorist attack may occur, and have asked for help from Swedish colleagues.
Norwegian citizens wanted for crimes in their home country have on several occasions fled to Sweden. A number of roads crossing the 1,630 km (1,010 miles) long border between the countries lack checkpoints.
Both Norwegian and Swedish police security agencies have declined to comment on the issue.
