Armed robbers have stolen dozens of artefacts from a museum in Ancient Olympia - the birthplace of the Olympics, Greek officials say.
Local mayor Thymios Kotzias told media two masked men had broken into the Archaeological Museum of Olympia after overpowering the sole guard.
He said items of "incalculable" value had been stolen, but gave no details.
Culture Minister Pavlos Geroulanos has tendered his resignation, state television reported.
The museum is seen as one of the most important cultural sites in Greece.