ANTALYA, Turkey 

Turkish Foreign Minister Mevlut Cavusoglu Monday said the banner calling for the murder of President Recep Tayyip Erdogan in a rally in the Swiss capital of Bern was “unacceptable”.

“It is unacceptable that a socialist party in Switzerland held a rally with PKK members or a terrorist organization and they use [these types of] slogans,” Cavusoglu told Anadolu Agency in southwestern Antalya province.

On Saturday, a rally, supported by the Social Democratic Party of Switzerland (SP) and the Swiss Green Party was held in front of the federal parliament building in Bern against Turkey’s constitutional referendum on April 16.

A large banner read “Kill Erdogan” picturing the Turkish president with a gun pointed at his head could be seen during the rally, which was also attended by supporters of the far-left terrorist group DHKP-C, and YPG, the armed wing of PYD, which is the Syrian offshoot of the PKK.

Referring to the banner, Cavusoglu said: "If it is not fascism, then what is it [called]? When we say this, they [Europe] are offended.”

“Isn’t it a support to a terrorist organization? It means you [the Swiss Social Democratic Party] are on the same line with terror and the terrorist organization.”

Criticizing Europe’s recent stance towards Turkey, he said: “Europe is going towards a cliff. […] May they give up having their heads in the sand.”

He added that Turkish people would have the final word in the April 16 referendum despite the “No” campaign.

On Sunday, Swiss authorities opened an investigation into the rally.

“We will follow the investigation. We will see which steps they will take,” the foreign minister said.

Reporting by Murat Egilmez; Writing by Nilay Kar