President Reuven Rivlin
President Reuven RivlinFlash 90

Israeli police announced Monday an investigation after a picture of President Reuven Rivlin wearing a kaffiyeh emerged amid anger over his decision to reject Elor Azariya's pardon request.

Rivlin had on Sunday refused to pardon Elor Azariya, who in January was convicted of manslaughter for shooting in March 2016 an Arab terrorist suspected of having an explosive vest.

Several politicians criticized Rivlin's decision, and Culture and Sport Minister Miri Regev (Likud) said Rivlin had "abandoned Elor Azariya and harmed the pardoning institution."

Rivlin's Facebook page quickly filled with messages of support but also scathing criticism, with responders telling him he was "no longer my president," as one wrote, or accusing him of "fawning to appease your Arab and left-wing friends," as another said.

MK Oren Hazan of the ruling Likud party -- the same Rivlin served in as an MK and later as a minister -- called on Rivlin to resign, and said pardoning authority should move from the presidency to the Knesset.

The image of Rivlin in a kaffiyeh was meant to equate Rabin to arch-terrorist and Palestine Liberation Organization leader Yasser Arafat, who wore a kaffiyeh regularly, and imply he was betraying Israel's interests.

Police said they had launched the probe after the image of Rivlin wearing a keffiyah was distributed on social media.

The statement did not elaborate on those being investigated nor the possible crime committed.

Posters of Israeli former Prime Minister Yitzhak Rabin in a kaffiyeh had appeared before his assassination in November 1995.

Rivlin's office meanwhile postponed an olive harvesting event at the presidential residence in Jerusalem set for Monday morning, citing "inclement weather," despite clear skies.

Azariya is due to remain in prison until October 2018.