Police on Friday warned against the use of banned flags and posters of the PKK terrorist group during the May 1 International Workers' Day.
In a statement, police in Berlin said it was aware of recent calls by several German political groups to carry PKK's flags and symbols during a rally at the capital on Tuesday.
"Such offenses against the Law on Associations will be prosecuted," the police said.
"Strict prosecution of such offenses might not be obvious at a first glance, but Berlin police records and documents such incidents to enable criminal prosecution," it added.
Germany outlawed the PKK terror group in 1993, following violent protests carried out by group members in the country.
In March this year, Germany's federal Interior Ministry updated its list of prohibited symbols used by the PKK, and also included posters of Abdullah Ocalan, PKK's jailed head, to this list.
Turkey has long criticized German authorities for tolerating PKK activities and pressured Berlin to take stricter measures.
The PKK, which is listed as a terrorist organization by Turkey, the U.S. and the EU, waged a terror campaign against Turkey for more than 30 years, killing nearly 40,000 people.
