The population in the makeshift refugee and migrant camp at Idomeni dropped further Wednesday as authorities relocated people to organized facilities elsewhere in Greece.
More than 2,600 migrants have been bussed away from the camp over the past two days, reported state broadcaster ERT, which is the only media that has been allowed to approach the site.
The camp is located near a fence marking the border with Macedonia, and is situated about a kilometre west of the Athens-Skopje highway.
The evacuation is expected to take several more days.
Police have not forcibly remove anyone, but among the 6,000 people still at the camp, there may be a "hardcore group" that will refuse to leave, internet portal in.gr speculated.
It is people from the group, mostly young North Africans, who rioted and blocked the railroad track running through the camp on several occasions over the past three months, it said.
Camp Idomeni was set up by the UN refugee agency in September, at the peak of the migration wave, to help people trekking along the Balkan route to wealthier northern Europe.
It initially comprised a group of large tents for around 2,000 people staying short-term, as well as medical and legal services.
The population grew rapidly in late 2015 and the conditions turned squalid as Macedonia and other countries began imposing restrictions on migrants entering their territory.
At the time the Balkan route was severed in March on the Macedonia-Greece border, around 12,000 people lived in the camp.