Justice Minister Antonis Roupakiotis on Tuesday claimed to have found photographs published by Greek police of four young men arrested in the course of a double bank heist in northern Greece and bearing obvious signs of injury as "chilling."

Speaking on Alpha radio on Tuesday morning, Roupakiotis expressed his horror at the photographs of the four youths, who were arrested last week for a double armed bank heist in Kozani and have been linked to the urban guerrilla group Conspiracy of the Cells of Fire. Police also believe the four men could be the perpetrators behind a bloodless bomb blast at The Mall in northern Athens last month.

"I was chilled by the pictures showing their swollen eyes and lips," Roupakiotis said.

"On the other hand -- and I am not trying to measure my words -- when you clash with someone wielding a Kalashnikov assault rifle, you can't be holding a flower," he added. "This sort of thing is violent by its nature."

Athens public prosecutor Panagiota Fakou has launched an investigation into claims that all four suspects were beaten while in police custody.

The intervention followed complaints by relatives after photographs of the four suspects, bearing heavy bruises to their faces, were published by police. Indications that some of the photographs were doctored, to conceal the presence of police officers’ hands constraining the suspects or to tone down the bruising, provoked strong criticism.