The recording, posted on an Islamist website by the Islamic State of Iraq, shows the security men kneeling and blindfolded with their hands tied behind their backs. A masked militant then shoots each one in the head with a pistol.

The militant group said it killed the men because a demand issued on June 11 for Sunni Muslim women prisoners to be released was not met.

Iraq’s interior and defence ministry officials were unavailable for comment on the footage.

The Al Qeada linked group has made similar demands after previous kidnappings, and has also claimed to have captured and killed three US soldiers recently.

The latest footage was posted on a site that jihadist groups in Iraq typically use to transmit messages.