Police in Greece have fired tear gas at anti-European Union protesters in central Athens.
Demonstrators tried to break the police cordon and storm a building where the bloc's leaders have gathered.
They are attending the opening ceremony of Greece's six-month presidency of the EU.
Left and right-wing opposition groups called for demonstrations, despite a police ban on protests.
Al Jazeera's John Psaropoulos reports from Athens.
Source: Al Jazeera