Two hooded robbers broke into an Olympics history museum in Greece with hammers, tied up an employee and stole 60 to 70 artifacts, authorities said. Athanassios Kokkalakis, a police spokesman, said the robbery Friday at the Museum of the History of the Olympic Games, occurred just after 7:30 a.m., CNN reported. The museum is in Olympia, birthplace of the Olympics. The robbers tied the hands of the museum\'s guard, then stole 65 to 68 small clay and brass statues and a gold ring, Kokkalakis said. There were no reports of injuries. Dimitra Koutsoumba, president of the Greek Archaeologists\' Association, said the artifacts were mainly Olympic-related figures -- statues of athletes.. Olympia Mayor Thymios Kotzias said items of \"incalculable\" value had been stolen, but did not elaborate, the BBC reported said. In January, three art works, including a painting by Pablo Picasso and another by Piet Mondrian, were stolen from the National Gallery in Athens.