The Islamic State militant group (ISIS) released images of a wheelchair-bound executioner purporting to crucify an alleged spy in the central Libyan city of Sirte late Tuesday.

The images, marked by the official logo of ISIS’s Wilayat Tarabulus (province of Tripoli) in which Sirte is located, are captioned with the words “the execution of spies in the city of Sirte” and show the murder of three accused spies.

The wheelchair-bound militant sits next to the alleged spy, kneeling before he is crucified, in front of an ISIS flag.

The group published the images in what appears to be an attempt to consolidate its hold over the former hometown of deposed Libyan leader Muammar Gaddafi amid a series of attacks against the radical Islamist group.