Top Iraqi Muslim cleric Grand Ayatollah Ali al-Sistani on Saturday demanded the release of 18 Turkish workers kidnapped in Baghdad by unknown militants, saying it harmed the image of Islam

Top Iraqi Muslim cleric Grand Ayatollah Ali al-Sistani on Saturday demanded the release of 18 Turkish workers kidnapped in Baghdad by unknown militants, saying it harmed the image of Islam.

The Turkish men, who were working on a football stadium project, were seized in Baghdad's Sadr City area earlier this month, and a group presenting itself as a Shiite group claimed the kidnappings in a video posted online.

"We demand the release of the kidnapped men and the end of such practices, which harm the image of Islam" in general and Shiites specifically, Sistani's office said in a statement.

Such actions also lead to "reducing the prestige of the state and weakening the elected government," the statement on Sistani's website said.

In the video, militants armed with submachine guns and wearing black uniforms, sunglasses and balaclavas stood behind the kidnapped Turks and identified themselves as "Furaq al-Mawt," or "Death Squads."

One of their demands was that Turkey order rebel forces to stop besieging four Shiite villages in northern Syria.

But this group may not be a Shiite one and its action could also potentially be to mislead, and the group's make-up and provenance were not immediately clear.

The demands, addressed to Turkish President Recep Tayyip Erdogan, also included Ankara stopping "the flow of militants from Turkey to Iraq," and "the passage of stolen oil from Kurdistan through Turkish territory."

"If Erdogan and his party do not respond, we will crush Turkish interests and their agents in Iraq by the most violent means," the group said in the video, which lacked the polished production quality found in most militant propaganda in Iraq.

Dozens of Turks have been kidnapped and released in Iraq in the past 18 months by the ISIL terrorist group, which overran large parts of the country last year.