One woman was wounded when a powerful bomb exploded on Thursday outside Greece's top-security prison.
An anonymous caller to the Greek daily Etheftherotypia and a private television station warned that a large explosion would go off at Greece's top-security prison of Korydallos, west of Athens.
Police said the mechanical device was discovered inside a garbage bin near the women's wing of the prison. The explosion was heard throughout Athens, and police immediately cordoned off the area to traffic.
One women suffered injuries to her legs from shattered glass, and the blast caused damage to the exterior of the prison and nearby buildings.
In March, a 15-year-old boy was killed and his mother and sister wounded after a bomb exploded outside a building in central Athens.