What should a traveler do in the absence, replacement or loss of a passport? Don’t panic because this issue is easy to solve. To buy a train ticket and board a train, you can use a foreign passport or a valid military ID (if you are currently serving). The international passport is valid even if the trip is planned on the territory of Russia.
If you don’t have a foreign passport or military ID, you need to go to the passport office and get a temporary identity card. It should contain your photo, full name and ID number.
A temporary identity card is issued upon request for a period of time until a new passport is produced by the Ministry of Internal Affairs. For help you can contact:
To any police station if the passport is lost or stolen;
To the department of the Ministry of Internal Affairs at the place of residence or stay – when replacing a passport with a new one.
Source: Starhit