1. The loss must be reported as soon as possible to the Greek / Cypriot police.
2. Contact the airline or your travel agency to check if they allow you to travel with a different type of ID (for ex. Norwegian driver's licence) and the police report. List with contact information for airline companies.
3. Contact the Norwegian Embassy or a Norwegian Consulate in order to report the loss of your passport, and for any assistance if the airline / travel agent do not accept that you return without further documentation.
The Embassy / Consulate can assist you in contacting the travel agent / airline, and in most cases it will be issued a certificate which is valid for the journey back to Norway.
In some cases it is necessary to issue an emergency passport, for ex. if you travel with Air Baltic via Riga, or if you travel via London. Emergency passports are normally issued for a limited period of time. You can apply for an emergency passport either at the Embassy in Athens or at the Consulate General in Cyprus. More information about emergency passports on the Norwegian police's website.