A spokesman for the Norwegian Railway Authority says parts of Oslo's central station have been evacuated as police investigate an abandoned suitcase.
Olav Nordli says the suitcase was found in the area where buses depart for Oslo's airport. Police have sealed off the area and are examining the abaondoned luggage.
The city is on high alert in the wake of Friday's bombing and youth camp shooting that killed 68 people.
The first Cabinet ministers were to return to their offices Wednesday after a car bomb exploded in the government district of the Norwegian capital.
Anders Behring Breivik, a 32-year-old Norwegian, has confessed to the attacks, according to police and his lawyer, but pleaded not guilty.