Three students from Middle East Technical University (ODTÜ) in Ankara were detained on Saturday on charges of insulting President Recep Tayyip Erdoğan by carrying a placard bearing a famous caricature of him, called “Tayyipler Âlemi” (The World of Tayyips), during the university’s graduation ceremony.

Özgür Mehmet Gür, ODTÜ student council president, was also detained on Sunday.

The caricature was first published in 2006 by the Penguen political satire magazine, against which then-Prime Minister Erdoğan filed a lawsuit. However, an Ankara court had dismissed the suit, citing freedom of expression.

ODTÜ’s graduation ceremonies for years have had a tradition of humorous and critical placards about current political developments in Turkey.

According to the Evrensel daily, 12 more detention warrants were issued for students carrying placards, while the police started to investigate video recordings of the event.

Among the students being sought is Serkan Özkan, who was carrying a placard saying “With this placard, we are behaving like Muharrem İnce had won.”

However, Republican People’s Party presidential candidate İnce, who was Erdoğan’s rival in the election on June 24, announced that he had canceled a meeting with ODTÜ students after the detention of student council president Gür.

During the graduation ceremony on July 6 students had also protested Rector Mustafa Verşan Kök, who was appointed by President Erdoğan, although he had not received a majority of votes in an intra-university election.

According to higher education laws, President Erdoğan has the authority to select any name among those offered him by the Higher Education Board.

After the protest against Rector Kök, private security personnel accosted the students to remove the placards from their hands, upon which some parents got involved in the confrontation.