Greek police say armed robbers have stolen about 60 ancient artifacts from a museum in Olympia.

The city's mayor, Efthimios Kotzas, told reporters that two masked assailants overpowered a museum guard Friday and seized valuable bronze and pottery artifacts from the museum dedicated to the ancient Olympic games.

“Two armed assailants went in during the change of guards. They were masked and armed. They tied up one of the guards.”

The Greek culture minister, Pavlos Geroulanos, submitted his resignation over the matter, but it was not clear whether it had been accepted by Prime Minister Lucas Papademos.

The heist is the second art robbery in Greece in the past two months.

In January, robbers stole three paintings by such greats as Pablo Picasso from the National Gallery in Athens.

The head of the Union of the Greek Archaeological Site Guards, George Dimakakos, says Greece's austerity measures have led to diminishing security for the country's antique treasures.

“In the past two years, the lack of security has become an even bigger problem. Because of public sector labor reserve scheme, as you know this too was part of the Troika measures, a large number of my colleagues were forced into early retirement in order to avoid the scheme, and secondly hiring is now prohibited.”

He said the museum had asked for reinforcements in the guarding of the site, but that the hiring is forbidden by law.

The value of the stolen treasures has not been estimated yet. Police have made not arrests and a search for the robbers continues.