The attackers painted star of David on the wall of Mevlana mosque, affiliated with the Turkish-Islamic Community National View (IGMG), head of the mosque foundation Hulusi Yuksel told Anadolu Agency.
Yuksel said they informed local security authorities about the attack as police launched an investigation into the case of vandalism.
"We don't know who made the attack," Yuksel said adding that the construction of the mosque has been ongoing for one and a half year.
There is no serious anti-Turkish or anti-Islamic hostility in the area except minor reactions against the mosque construction, according to Yuksel.
Germany, a country of over 81 million people, has the second-largest Muslim population in Western Europe after France. Among the country’s nearly 4.7 million Muslims, 3 million are of Turkish origin.
In recent years, the country has seen growing Islamophobia and hatred of migrants triggered by propaganda from far-right and populist parties.