Leaders of Greece's neo-Nazi group Golden Dawn found guilty of running criminal organization

Riot police used water cannon during clashes with anti-fascist protesters after the Golden Dawn leadership was found guilty in Athens on Wednesday.

Athens, Greece (CNN)The leaders of Greece's neo-Nazi group Golden Dawn were found guilty Wednesday of forming and running a criminal organization under the cloak of a political party, in a landmark decision hailed as a victory for democracy and human rights.

Following a marathon trial lasting five-and-a-half years, an Athens court deemed that crimes by Golden Dawn members including murder, attempted murder, assault and possession of weapons were not the actions of individuals operating on their own initiative. Instead they were directly planned and ordered by a party leadership that employed violence to eradicate perceived enemies.
Eighteen former party lawmakers, including leader Nikos Michaloliakos, a holocaust denier who founded Golden Dawn in the 1980s as a neo-Nazi organization, were among those found guilty on Wednesday. Individual sentences are to be announced in the coming days.
    Presiding judge Maria Lepenioti sits in the supreme court as she announces the verdict in the trial of suspected Golden Dawn members.
    There was a strong police presence around the court on Wednesday as left-wing parties, trade unions, and anti-fascist and human rights groups staged rallies to coincide with the verdict.
      Protesters and riot police then clashed after the ruling. Police said a peaceful crowd of at least 20,000 people dispersed, but minutes after the verdict was announced, a smaller group of around 600 people attacked officers with stones and Molotov cocktails.
      Riot policemen try to avoid flames from a petrol bomb thrown by protesters on Wednesday.
      Prime Minister Kyriakos Mitsotakis tweeted that it was a "truly historic day for Greece, democracy and the rule of law."
      "Αfter the Greek people voted the neo-Nazi party of Golden Dawn out of Parliament in the last election, today the Greek justice system convicted its leadership of operating as a criminal organization," he added.
        The Golden Dawn leaders have denied the charges from the start, claiming they are victims of political persecution.
        Dozens of others -- party members and alleged associate -- have been convicted on charges that range from murder to perjury. Most of these are linked to violent attacks between 2012 and 2013. They include the fatal stabbing of popular anti-fascist hip hop singer Pavlos Fyssas and attacks on immigrants and left-wing activists.
        The decision concludes over 450 days in court and hundreds of testimonies and hours of data collected from the cellphones and laptops of those arrested. These include photos of Golden Dawn recruits at training camps posing with assault weapons and giving Nazi-type salutes.
        "There is clear and unequivocal message in this landmark case, that hate crimes will no longer be tolerated, [the decision] can also have a significant impact on preventing racist violence in future," Nils Muiznieks, head of Amnesty International Europe, said ahead of the verdict.
        Thanassis Kambagiannis, a lawyer from the prosecution team, has described the trial as "the largest court hearing of Nazis since Nuremberg."
        The trial started in April 2015, with close to 70 members of Golden Dawn charged under the so-called "mafia clause."
        Protesters at the anti-fascist rally, embrace each other following the announcement of the verdict, outside the courthouse in Athens on Wednesday.