Images released Tuesday by the Islamic State group purport to show the beheading of four men accused by the terrorists of recruiting pro-government fighters in Iraq, Israel National News reported. The photos, whose authenticity has yet to be verified, show four black-clad men kneeling in an empty street somewhere in Salaheddin province where Iraqi troops have been clashing with fighters for the Islamic State group, also known as ISIS, over control of Tikrit.

The photos depict men with knives standing behind the four men in the street before beheading them. The terrorist group said the prisoners had been recruiting militia fighters to take up arms against the Islamic State group in Salaheddin province. It was unclear where exactly the images were taken.

The radical Sunni Islamist group known as ISIS, ISIL and the Islamic State has been terrorizing parts of Iraq and Syria since last summer. The group has released a number of videos graphically depicting the beheadings of prisoners in its custody. Last month, video footage emerged of ISIS beheading 21 Egyptian Coptic Christians kidnapped in Libya. The footage was reportedly recorded in Tripoli, Libya, and was posted to social media Feb. 15.

On March 2, fighters for the Iraqi government mounted an assault on ISIS-controlled Tikrit, the capital of the Salaheddin province and the stronghold of ousted and executed President Saddam Hussein, in an attempt to regain control of the city. The Iraqi army’s offensive stalled Tuesday in the face of strong ISIS opposition.  

"The battle to retake Tikrit will be difficult because of the preparations [the Islamic State] made," Jawwad al-Etlebawi, spokesman for Asaib Ahl al-Haq, a Shiite militia at the center of the charge on Tikrit, told the Agence France-Presse. "They planted bombs on all the streets, buildings, bridges, everything. ... Our forces were stopped by these defensive preparations.”