Athens - A package containing dynamite and cables was sent to Greece's stock exchange on Thursday but was safely detonated by the bomb disposal unit, police said.
The device, held together by clothes-pins, lacked a mechanism to set it off, so would not have exploded by itself, a police official said.
A stock exchange official said the package was discovered mid-morning at the building's entrance but did not affect the trading session, which continued without interruption.
Shares on the Athens stock index were up 2.2 percent in afternoon trade.
The anti-terrorism force is investigating and the contents of the destroyed parcel are being tested, police said.
In 2009, a powerful car bomb exploded at the stock exchange, slightly wounding one person and damaging the building.
An anarchist guerrilla group claimed responsibility.
Small-scale bomb and arson attacks are frequent in Greece, which has a long history of anarchist and far-leftist violence.
The attacks, often in the name of anti-austerity protests, have picked up in recent years as the country struggles through its deepest economic crisis since World War Two.
A car bomb exploded at a central bank building on April 10, hours before Greece sold bonds to foreign investors for the first time since being bailed out four years ago by the European Union and International Monetary Fund.
It caused no injuries but smashed windows in one of the busiest streets in the capital.
Investors are jittery over Greece's future, as a weak right-left coalition government gambles on ending the unpopular 240 billion euro (R3.4 trillion) bailout arrangement early, forgoing some of the IMF money, in order to shore up its political support. - Reuters