Six people arrested during police raids in the Athens area and on the island of Crete have been charged with belonging to a terrorist organization and possession of firearms and explosives.

The five men and one woman are to appear in court Tuesday.

The charges do not identify their terrorist organization, but previous arrest warrants against two of the suspects linked them to the radical Greek anarchist group Conspiracy Nuclei of Fire.

Greek police chief Lefteris Oikonomou said Sunday that ballistic tests on the weapons seized during Saturday's raids have failed so far to connect the suspects to any known terrorist attacks.

Police had hoped the raids would establish a connection between the Conspiracy Nuclei of Fire and another Greek radical group, Sect of Revolutionaries.

Of the two, the sect has been the most violent one, killing an anti-terrorism police officer guarding a witness in a terrorism trial in June 2009, and a journalist in July.