André is correct. They are from the DDR.
It's not a stamp but a "Spendenmarke" from the Dynamo Sport Club. They are part of the 1975 set:http://www.ddr-spendenmarken.de/Spo...namo_H75.php
As I understand the system, a person contributes to an organization and receives a Spendenmarke in return. Some organizations even provided albums for their "stamps." The 1975 "album" is on the upper left. They have no postal use.