A senior officer of the Greek Police on Tuesday expressed concern that Costas Sakkas, a 30-year-old self-proclaimed anarchist charged with participation in an urban guerrilla group, may turn to violence after violating the terms of his conditional release. According to the officer, who wished to remain unnamed, authorities have no clues as to Sakkas’s whereabouts after he failed to report in to his local police precinct in Kaminia in Piraeus by midnight on Monday. “We catch them on the one hand, and, on the other, they are let go,” the police officer told Skai on Tuesday afternoon. Another officer, serving with Greece’s counter-terrorism unit, estimated that Sakkas decided to cut loose because he was due to post 15,000 euros in bail on Tuesday imposed by a prosecutor as part of the terms of two separate release orders. According to the source, Sakkas was first arrested on December 4, 2011, when a large counter-terrorism operation in Athens and Agrinion, central Greece, linked him to properties used as arms caches by Conspiracy of the Cells of Fire, an urban guerrilla group that has been active since 2008 and was linked to a number of bloodless bomb attacks targeting public figures as well as a series of letter bombs sent to embassies and foreign governments in 2010. Sakkas, who claims to be an anarchist but denies any links to the group, was released from pre-trial custody following a hunger strike in protest at the expiration of his custodial terms in the summer of 2013. He was re-arrested on January 7 this year when his fingerprints were identified in another property linked to Conspiracy of the Cells of Fire in the northern Athenian suburb of Halandri. A prosecutor subsequently granted him release, on the condition that he post bail and report to his local precinct every Monday.