By Cuneyt Karadag

BERLIN

Turkey's embassy in Berlin sent a diplomatic note to the German Foreign Ministry on Tuesday over what it called "a provocative act" staged in the German capital.

Protesters unfurled a banner in front of a motor vehicle featuring an image of the Turkish president among other leaders, reading: "Do you want this car? Kill dictatorship."

The Turkish embassy said the German authorities had failed to intervene in the "violent protest" which took place in front of the federal prime ministry building in Berlin.

"It is obvious that such actions, which are to encourage hatred and violence in a sensitive period when societies need to protect their peace and common values, will not serve peace," the statement read.

Images of Russian President Vladimir Putin and Saudi King Salman bin Abdulaziz were also on the banner which was unfurled by the protestors from the "Center for Political Beauty" art collective.

The Turkish Foreign Ministry also condemned the protest.

In a written statement late Tuesday, the ministry said the banner included written expressions openly calling for an attempt against the lives of leaders whose images were displayed on the banner. 

"What is more perilous is the presence of German police at the area where the protest was made and its non-intervention," the statement stressed.

It also said Ankara was waiting for German authorities to take the necessary steps regarding the incident.

G20 leaders -- including Erdogan and Putin -- will gather in the German city of Hamburg later this week for an international summit.