(CNN) -- A Greek journalist was shot and killed Monday outside his apartment in a residential part of Athens and police say the killing may be linked to a far-left extremist terrorist group.
Someone knocked on journalist Sokratis Giolias' apartment door and told him his car had been stolen, police said. When Giolias, 37, stepped out of his home, he was killed.
According to a statement released by the Criminal Investigations Division of the Greek Police Force, Giolias was shot and killed by two handguns previously used by the "Sect of Revolutionaries," which allegedly shot and killed a police officer in June 2009.
"Ballistic tests on 16 casings retrieved from the site" showed they "were fired from two weapons previously used in operations by the terrorist organization," police said.
The Sect of Revolutionaries emerged after Greece's widespread rioting in December 2008 that was sparked by the fatal shooting of a teenage boy by police.
The group has vowed to carry out attacks against police and the news media, which it accuses of helping corrupt business interests mislead public opinion.
No one has claimed responsibility for the attack.
Athanasios Kokkalakis, spokesman for the civilian protection ministry, said there is "no reason to believe that [Giolias] personally could be a target of a terrorist group -- other than the fact that he is a journalist."
"Any journalist could be a target just as any police officer could be a target."
The investigation of the shooting is being conducted by the Special Crimes Divison agaist Violence.
Initial reports said three men were involved in the shooting. The car they escaped in was later found abandoned and torched, police said.
It had been reported stolen Saturday.
Giolias was a director of the national news radio station "Thema 9.89," and wrote for the blog Troktiko, which often reported on scandals.
He also worked closely with Makis Triantafyllopoulos, a Greek journalist famous for his investigative reporting.
CNN's Mila Sanina and Christine Theodorou, and journalist Elinda Labropoulou contributed to this report.