A mosque in the central German city of Kassel has been attacked with Molotov cocktails on early Sunday morning.

Axar.az reports citing Turkish media.

The attack caused no casualties but minor damage to the mosque belonging to European Turk Union (ATB), one of the largest Muslim-Turkish associations in the country.

In the attack organized by four assailants -- who were identified on security camera -- some window glasses of the Yunus Emre mosque were broken, the frames were partially burned and the walls of the building were damaged.

Incident took place at around 4.30 a.m. local time (0230GMT) in the central Kassel city of Hessen province.

Mustafa Koc, head of cultural center which runs the mosque, said: “We want police to catch all people responsible for the attack.”

"The continuation of such attacks increases our worries. We expect authorities to move and act urgently to solve these problems. We call on the whole Turkish community to remain prudent,” Koc added.

At least 38 attacks on various forms have been recorded since the beginning of this year in Germany.

The PYD/PKK group and far-left organizations claimed responsibility for more than two dozens of attacks since launch of the Turkish military-led Operation Olive Branch in Syria’s northerwestern region of Afrin against YPG/PKK-Daesh terrorists.

The attacks targeted Turkish mosques, associations and shops in various cities, including Berlin, Frankfurt, Hamburg, and Aachen.

German police have failed to arrest assailants in most of the incidents.

The PKK has been banned in Germany since 1993, but it remains active, with nearly 14,000 followers in the country.

Ankara has long criticized Berlin for not taking serious measures against the PKK, which uses the country as a platform for their fund-raising, recruitment, and propaganda activities.

Germany has a 3 million-strong Turkish community, many of whom are second- and third-generation German-born citizens whose Turkish grandparents moved to the country during the 1960s.