Greek riot squad bus blast raises security fears

A roadside bomb blast targeting a police convoy in Athens early on Friday caused no injuries but alarmed authorities who had been insisting that Greece's leftist guerrillas were defeated.
The explosion was the first of its kind in Greece for over a decade and the first bomb attack since the end of this summer's Athens Olympics, Europe's biggest peacetime security operation.
"Police are treating this explosion very seriously because it has been a long time since something like that has taken place," a police source said. "This was a well-planned strike, something that has not happened in years."
The device exploded as two riot squad buses drove along Petrou Ralli avenue on their way to the top security Korydallos prison in western Athens, police said.
It was tied to the road's metal barrier and detonated from a nearby park through a 30 metre (yard) cable, they said.
"There are no injuries or material damage," Athens police chief Vassilis Tsiatouras told reporters. "It was a rather small device."
There was no claim of responsibility for the attack and the authorities did not say who they thought was behind it. But it was widely assumed to be the work of leftist guerrillas.
The government condemned the attack as a threat to democracy, saying it was pure luck there were no casualties.
"We will not allow anyone to damage the sense of security enjoyed by the citizens and to challenge our democracy," spokesman Thodoris Roussopoulos said in a statement.
Throughout the 1980s and 1990s, radical leftist groups including the notorious November 17 organisation carried out bomb attacks on police and official targets in Greece.
The Greek authorities declared victory over the guerrilla groups two years before the Athens Olympics with dozens of high-profile arrests and convictions.
However, there have been attacks since then. A bomb went off in central Athens 100 days before the Games, and in the past few days there has been a spate of crude attacks in the capital using firebombs and camping gas canisters.
The device used in Friday's attack was the most sophisticated seen in several years.
It was also the first time a police bus had been targeted since 1992, when a bomb planted by the Revolutionary Popular Struggle (ELA) injured several officers.