Hello Yamal:
In principle, it is possible to open an account. However, to do this you will generally need to have valid identification. Since these papers are often lost when fleeing one’s homeland, the Federal Ministry of Finance (Bundesministerium der Finanzen), the Federal Financial Supervisory Authority (Bundesanstalt für Finanzdienstleistungsaufsicht), and the German Savings Banks Association (Deutsche Sparkassen- und Giroverband) have agreed that, for now, a registration certificate or a certificate of permission to stay including a photograph will be sufficient to open an account at the municipal and district savings banks in those areas.