Turkish authorities on Tuesday seized and jailed a 16-year-old youth for drawing a mustache on an election campaign poster showing re-elected President Recep Tayyip Erdogan, media reports said.

Several media close to the opposition, including daily newspapers BirGun, Cumhuriyet and private TV station Halk TV, said the youth from the southeastern town of Mersin was accused of defacing the poster near his home with a pen, scribbling “a Hitler mustache and writing insulting comments.”

He was arrested after being identified by CCTV cameras, media reports said. Authorities interviewed him at his home where he reportedly “admitted drawing the mustache” while denying writing the accompanying comments.

Taken before the public prosecutor he was found to have “insulted the president” and was jailed at a nearby youth facility, according to Halk TV.

Erdogan extended his 20-year rule over Turkey after winning the May 28 second round of the presidential election to embark on a new five-year term.

According to the justice ministry, “insulting the president” is one of the most common crimes in Turkey, resulting in 16,753 convictions last year.