Germany's Foreign Ministry is warning that Turkey might take "further measures" against German journalists after reporters were denied accreditation in recent weeks.

The Foreign Ministry updated its travel advice late Saturday for Germans planning to go to Turkey. It said Turkish authorities refused to issue to several journalists the permits needed to report from the country.

The ministry said "as such, it can't be ruled out that the Turkish government will take further measures against representatives of German media as well as civil society organizations."

The ministry also cited Turkey's "arbitrary arrest" in recent years of German citizens suspected of links to banned groups, such as the network of a Turkish cleric living in the U.S. Turkey accuses followers of Muslim cleric Fethullah Gulen of being behind a failed 2016 coup.