"Together we will do everything to reveal the background of the attacks," the official said on Friday.
The statement followed findings of German investigators, who revealed that perpetrators of both attacks had close contacts to possible Daesh masterminds via a mobile messenger. One of the phone numbers in the chat was from Saudi Arabia.
On July 24, a Syrian national, whose asylum application had been turned down and who was to be deported to Bulgaria after living in Germany for a year, detonated a bomb in the Bavarian city of Ansbach, killing himself and injuring 15 bystanders.
Earlier in July, an Afghan refugee attacked train passengers in Wurzburg with an axe and wounded several people. The police shot the attacker dead.
The Daesh terror group, outlawed in Russia, claimed responsibility for both attacks.
