THESSALONIKI — A day after police said they had reduced tension outside a northern Greece high school, trouble erupted again when a group of some 100 youths thought be to right-wing provocateurs blocked the entrance to another school and tossed projectiles at anyone trying to stop them.

Their targets were journalists and teachers too, who had to duck stones and flares and other objects tossed by the troublemakers hiding behind dumpsters they used as barricades.

The incident happened outside a vocational training high school in the western suburb of Evosmos, said Kathimerini, although it wasn't clear whether pupils of the school are among them but that were reportedly linked to far-right groups.

The first onslaught happened in western Thessaloniki first at another vocational training high school, in Stavroupoli, when right-wing rioters attacked students who were holding a peaceful protest against another attack on students handing out left-wing leaning fliers.

Police arrested a half dozen youths after that and said the attackers were being egged on by right-wing extrements including a youth wing of the disbanded neo-Nazi Golden Dawn party whose former leaders and dozens of members are in jail after being convicted of running a criminal gang and murder..

Media footage from both schools has shown several of the black-clad youths giving the Nazi salute, which led to praise being poured on them by far-right wing websites and social media pages applauding the violence.

Several pupils have been identified as being connected to the violence earlier this week and face indefinite suspension from school, the paper said, which is rare in Greece as students can get away with almost anything with impunity.

The tension in the area spilled over outside the Stavroupoli school after members of the parent-teacher association were prevented by a police cordon outside the facility from meeting with school authorities.

The violence in Thessaloniki has brought worry that a year after the Golden Dawn hierarchy was jailed that sympathizers and supporters are rising again across the country.

There's been no denunciation from the New Democracy government which has ministers who previously had sympathies aligned with right-wing extremists and neo-Nazi elements, showing them support.