Turkish President Recep Tayyip Erdogan has vowed to seek justice over a cartoon that authorities say disrespected the Prophet Muhammad, sparking angry protests in Istanbul late Monday and resulting in the arrest of the cartoonist who drew it. 

“Those who are rude to our prophet will be called to account. We will be watching,” Erdogan told members of his ruling Justice and Development Party (AKP) in Ankara today. “Defending the memory and the legacy of our beloved prophet who illuminates our path is our main duty. That which was done under the cover of humor was a lowly provocation,” Erdogan noted, after praising Muhammad at length. 

Turkish police violently detained four staff members of the storied Turkish cartoon magazine Leman, including cartoonist Dogan Pehlevan, in the early hours of Tuesday over a drawing that was perceived as depicting the Prophet Muhammad and the Prophet Moses. They are shown exchanging greetings amid a shower of missiles. The arrests came as throngs of protesters chanting Islamist slogans stormed Leman’s office in Istanbul’s Beyoglu district, which is a hub for late-night revelers. They called for the magazine to be shut down and for its owners and cartoonists to be punished, amid a wave of hate speech directed at the publication on social media.

Erdogan’s comments bode ill for Leman as prosecutors will likely be taking their cues from him, government critics say.