According to the police, several young people attacked the entrance to the synagogue and set a fire there. When the police arrived they found the door had had its glass shattered and discovered leaflets written, presumably, in Arabic.
"Currently, the synagogue's security, which was in place before, has been increased", the police said, refraining from specifics out of "strategic concerns".
Meanwhile, police in Berlin declined to tell Sputnik whether they had boosted security at synagogues in the German capital.
"Synagogues are traditionally under protection, [and] we cannot tell the press if this protection has been increased out of security concerns", the police explained.
They did mention arresting 10 people during an anti-Israel protest on 9 May after a group of teenagers attacked law enforcement officers near the Hermannplatz subway station. Sixteen officers were injured during the operation.
The Bonn attack took place amid an ongoing escalation in hostilities between Israel and the Palestinians.