The number of PKK sympathizers in Germany has increased since last year, the country's domestic intelligence agency revealed in its recent research.

According to the 2017 report of the Federal Office for the Protection of the Constitution (BfV), the number of PKK sympathizers in the country is 14,500, an increase of 500 since 2016. "The PKK continues to be largest terrorist group in Germany in terms of number of members and power," the report suggests.

Formed in 1978, the PKK terrorist group has fought a long separatist battle with the Turkish state. Its terror campaign has killed more than 40,000 people, including women and children.

The PKK is listed as a terrorist organization by Turkey, the U.S. and the European Union.

The report also reveals that the terrorist group collected 25 million euros in Europe, including 14 million euros in Germany. The BfV report also said that many PKK-linked organizations and foundations have changed their name to reflect positive impressions in recent years.

The leadership in northern Iraq controls the structure of the terrorist group in Germany and Europe, according to the BfV report, which adds that violence is still used by the PKK.

Northern Iraq's Qandil mountain range is thought to be the hideout for PKK leadership and is the headquarters of the PKK and its Iranian affiliate, the Kurdistan Free Life Party (PJAK).

The report also drew attention to the presence of other terrorist groups in Europe. It revealed that the Revolutionary People's Liberation Party-Front (DHKP-C) has 650 members in Germany and has carried out propaganda activities via various foundations.

The DHKP-C was founded in the 1990s after it splintered from a larger group of far-left organizations responsible for a string of attacks that include the assassination of two politicians in 1980 and several intelligence officials. The group was behind a suicide bombing that targeted the United States Embassy in Ankara in 2013.

Also, while the outlawed Turkey Communist Party/Marxist-Leninist (TKP/ML) has 1,300 members, another terrorist organization, the Marxist-Leninist Communist Party (MLKP), also has 600 members in Germany, the report said.