AFP - An explosive device went off outside a maximum security prison near Athens on Thursday, injuring one person, after an anonymous tip-off to Greek media, a police source said.
"There was an explosion at Korydallos after an anonymous phonecall to Eleftherotypia daily and Alter television station," the source told AFP.
A young woman is believed to have been injured by broken glass after the explosion, the police source said, adding that the device had been placed outside the wall of a disused section of the prison.
The device was hidden in a travel bag, Greek media reported.
Police cordoned off a busy avenue adjacent to the prison.
Bombings against state buildings and businesses, usually carried out by far-left extremist groups are common in Greece, but are usually designed to avoid causing injury.
The police recently arrested six alleged members of the country's leading extremist outfit Revolutionary Struggle whose attacks include a rocket strike against the American Embassy in Athens in 2007.