Greek police officers, protesting over new austerity measures, have defied their own colleagues in the riot force and blocked the entrance to a station.
About 50 members of the Greek Police Officers' Association picketed police facilities at Zografou, north-east of central Athens, preventing buses used for transporting riot police from leaving the site.
The buses are scheduled to travel to the northern city of Thessaloniki, where weekend anti-austerity demonstrations are planned.
The police protesters oppose salary cuts to be included in a new 11.5 billion euro (£9 billion) austerity package for 2013-14.
Later on Thursday, they are planning a protest rally in central Athens with officers in uniform joined by colleagues from the coast guard and fire service.