Not far from the Athenian ruins where democracy was born more than 2,500 years ago, young anarchists intent on toppling Greece's political system run a cafe where the beer is cheap and the artwork features police cars set on fire.

At first glance K*Vox, started a year ago by anarchists who occupied a shuttered building, looks like any other cafe in the bohemian Athens neighborhood of Exarchia. But inside posters show gun-toting guerrilla fighters and the symbol of anarchy - a circle with an A.

On a recent summer day, as the cafe was abuzz with chatter about two anarchists detained by police, a man barged in shouting that help was needed at a store attacked by far-right activists. Such extremists have been regularly blamed for the rise in street attacks during Greece's economic crisis, though they deny perpetrating such acts.

"Isn't it time for a revolution?" a 34-year-old anarchist watching the cafe scene said as he rolled a cigarette. "It's now or never. If we don't do something now, nothing will ever change."

Most media coverage of political radicals in Greece has focused on the far-right Golden Dawn party, which has risen to as much as 14 percent in voting polls after winning support with free food handouts for Greeks and fierce anti-immigrant rhetoric. But the country's economic crisis is also driving extremism on the left.

As Greece's economy has declined, anarchist groups that aim to topple the political system, saying it serves the interests only of the rich, have attracted growing public support.

"In the past it used to be more of a youth movement," said the cafe customer who, like other anarchists interviewed, declined to give his name. "Now you see anarchists who are 40, 50 or even 60 years old - not just 20-year olds like it was a few decades ago."

Many self-proclaimed anarchists - the word stems from the Greek "anarchia" or absence of authority - say they are pacifist, but certain groups have few qualms about using violence. Six years of recession have fuelled a new wave of left-wing militancy, according to officials, anarchists and court testimony.

Many "see it as an alternative political voice," said Mary Bossis, a University of Piraeus professor and one of Greece's foremost experts on left-wing militancy. "They are not marginal anymore."

Not a hoax

In the early hours of June 7, two Greek news organizations received a call warning that a bomb would soon go off in the residential Athens neighborhood of Dafni.

"This is not a hoax," the caller said before hanging up.

Twenty minutes later, a bomb with at least 1 kg of dynamite exploded under a BMW car used by Maria Stefi, the director of a high-security prison in Athens where suspected anarchist guerrillas are being held. The explosion destroyed the car and smashed windows in nearby buildings; Stefi, who was not in the vehicle, was unharmed.

A day later an anarchist group called the Conspiracy of Fire Cells claimed responsibility for the bomb. The blast was one of a series of attacks this year that have jangled nerves in Athens, including an explosion in a shopping mall, a drive-by shooting at an office used by Prime Minister Antonis Samaras and several gas canister explosions outside the homes or offices of politicians and journalists.

There were 527 arson and bomb attacks in 2012 and 254 in the first six months of this year, police data show. Security and police officials blame most of the attacks on anarchist or leftist "anti-establishment" groups.

The numbers compare with 542 arson and bomb attacks over the 12 years from 1974-86, when Greece had a reputation for widespread violence by leftwing militants, though attacks in that period had more bloody results.

Anarchist groups that have claimed responsibility for recent violent attacks include the Lovers of Lawlessness, Wild Freedom and Instigators of Social Explosion, Gangs of Consciousness, Lonely Wolf, the Untouchable Cell of Revenge and most recently, Untamed Desires, which said it was behind a parcel bomb sent in July to an association representing prosecutors.

But the group that has become most prominent since the economic crisis erupted is the Conspiracy of Fire Cells (CFC), which is accused by police of carrying out about 150 criminal acts since 2009. Its bombs typically contain small amounts of explosives packed into pressure cookers or similar containers. One such device exploded outside parliament in 2010, causing minor damage but no injuries.

Arrests of more than 30 suspected CFC members since 2009 and four trials since 2011 have failed to stem attacks by the group, which analysts say epitomizes the newer generation of anarchists who come from wealthier families and care little about ideology. Many are educated, disaffected youth who often describe themselves as "nihilist," unlike the more Marxist-inspired far-left militants of the past, analysts and lawyers say.

The CFC's loose, horizontal structure of individual cells makes it hard to fight, officials and lawyers say. Some liken the group to the Hydra, the mythological serpent that grew two heads for each one cut off: "You catch one but then more keep popping up," a former senior security official told Reuters.

One indication of the group's philosophy is a 2011 pamphlet attributed by prosecutors to CFC members - and confirmed as a CFC document by a lawyer acting for a CFC member - that was circulated on anarchist websites. It declares CFC members are "revolutionary anarchists" waging "urban guerrilla warfare" against the state.

The pamphlet says: "Everyone can learn and devise ways to steal cars and motorcycles, fabricate license plates and forge ID cards and official documents, expropriate goods and money, target-shoot and use firearms and explosives." It encourages anarchists to employ easily obtainable items such as gasoline, jerry cans, and camping gas canisters for attacks, as well as time bombs built using instructions from the Internet.

A former senior security official said that in some ways CFC poses a bigger security risk than other Greek militants such as Revolutionary Struggle (RS), an anarchist group that emerged in 2003 declaring war on all forms of government and later protesting against austerity.

Three self-proclaimed members of RS were arrested in 2010 and sentenced to jail in April this year. The authorities say the group, which blamed the capitalist system and corrupt politicians for plunging the country into crisis, and sought the support of ordinary Greeks, has been dismantled.

"Revolutionary Struggle ... didn't have any intent to kill," the former security official said. "The Conspiracy of Fire Cells are wilder and more frivolous, they could have an accident."

The CFC pamphlet says the group has no interest in representing anyone or any class. The former security official added: "You should not underestimate that the organization consists of very angry young people who don't have anything to hope for."

The catalyst

The CFC and other anarchists say they are left with no choice but to fight a state that is repressive. In particular, they accuse the police force, which is widely seen as being sympathetic to Golden Dawn's far-right activists, of brutality.

The police deny such accusations. Greek police immediately investigate any case of police violence that is reported, Christos Parthenis, a police spokesman, said in an emailed statement. He added that the police are legally allowed to use force when a suspect resists arrest.

Some ordinary people feel anarchists are the only effective front protecting illegal immigrants and leftists against Golden Dawn, which has become the third most popular party and won seats in parliament for the first time last year.

For many younger Greek anarchists, the turning point came in 2008 when police shot dead 15-year-old Alexandros Grigoropoulos in Exarchia. Police said the shooting was accidental after a verbal confrontation with youths; but the death of Grigoropoulos, the son of a jeweler who grew up in the posh Athens neighborhood of Psychiko, triggered weeks of rioting. A policeman was later convicted of murder over the incident.

"Grigoropoulos' killing was the catalyst," said the mother of a suspected CFC member now on trial in Athens. "They (the anarchists) realized their strength, they felt they could bring change and that people were on their side."

Among those affected was Nikos Romanos, a close friend of Grigoropoulos who was with him the night he was killed. In February this year Romanos was arrested, along with three other suspects, for robbing a bank. He declared he was an anarchist, though he denies being part of an armed group.

Public reaction to the case indicated the change in Greek attitudes. When it emerged that police had digitally altered Romanos' mugshot, and those of the other three suspects, to hide bruises sustained during their arrest, the four quickly rose to near-hero status in many people's eyes.

Leftist commentators and blogs accused the police of heavy-handed tactics. Police denied that, saying the injuries stemmed from the suspects resisting arrest.

Public sympathy was apparent when one alleged member of CFC, Costas Sakkas - who denies being a member of the group but says he is an anarchist - began a hunger strike in June to protest his 31-month detention without trial. Mainstream leftist parties and labor unions expressed outrage at his plight. Some actors and lawyers threatened to go on hunger strike themselves, while protesters briefly occupied tourism offices in Crete.

In July, a judicial council ruled that Sakkas be released on bail for health reasons. He was banned from leaving Athens and has to report to police authorities regularly, and still faces charges of being a member of the CFC.

Support for anarchists was also evident in January when police raided a popular squat in Athens frequented by anarchists. The raid brought 10,000 protesters on to the streets.

Law enforcement officials say they are just doing their job in cracking down on anarchists. Parthenis, the police spokesman, said in a statement that the force does not "take measures against political movements under any circumstance", but that anyone who takes part in groups that carry out bomb and arson attacks should be prosecuted.

Trials and defiance

Suspected members of outlawed guerrilla groups that Greece considers "terrorist" organizations are tried in a special court room. It was set up inside an Athens prison a decade ago to deal with the members of the deadly November 17 leftist guerrilla group, who are now jailed in an underground wing reserved for them. That group has not claimed any attacks since its leaders were arrested in 2002, but the court remains busy.

"It's not accidental that these trials against anarchist groups that police call terrorist are conducted in special conditions, special courts and before special judges," said Dimitris Katsaris, a lawyer for an anarchist who has denied involvement with guerrilla groups. "Everything is special in this case. It's the state that has declared war against freedom, not anarchists against the state."

Greece's public order ministry declined to comment. A government official who spoke only on condition of anonymity said: "This government's main principle is to uphold the law. We no longer tolerate such (violent anarchist) incidents or fail to act like in the past. We have won many battles in the fight against terrorism." At the same time, he said, "politicians need to stop stoking violence with inflammatory rhetoric."

Unlike other leftist guerrillas who have used their trials to make passionate statements about their aims and beliefs, CFC members have made clear they do not see the courts as legitimate - even mocking judges as having "expressionless faces", "well-fed bellies" and "fat salaries."

They have responded to questions in court with hostility and bored indifference.

"We know that you will sentence us and we don't care," Christos Tsakalos, 34, a self-proclaimed member of the CFC told a judge in March while being tried on charges including membership in a guerrilla group and attempted murder. "We want this to be over. We've told you we are members of the Conspiracy of Fire Cells, so go ahead and convict us."

Like other self-proclaimed CFC members, he did not respond to any charges because he refused to recognize the prosecuting and investigating authorities.

Tsakalos, who prosecutors say is a CFC leader though the anarchist group denies it has any leaders, was last year sentenced in a separate trial over attacks claimed by the CFC. He was given seven years in prison for participating in a "terrorist" group. In a statement published on the Internet, he said the sentence was so short that he had been teased by his "comrades" for it.

The CFC's mood of defiance was summed up by Spyros Fitrakis, a lawyer representing one self-proclaimed CFC member. He told Reuters: "We have entered a new phase ... they're rejecting the basic structure of the democratic political system we have as a country right now." [Reuters]