The operation comes more than a week after a fire burned down Greece's biggest migrant camp in Lesvos island, leaving thousands of refugees in need of emergency housing.
Greek police have begun moving hundreds of migrants stranded on the island of Lesvos into a new temporary tent camp on Thursday.
This development comes more than a week after a fire burned down Greece's biggest migrant camp, Moria, leaving thousands of refugees in need of emergency housing.
The operation, including 70 female officers, was intended to protect public health, police said.
"The operation began with many officers in white bodysuits, things are calm and migrants are slowly streaming into the new camp," a witness said.
The fire that gutted the Moria facility a week ago left over 12,000 people, most of them refugees from Afghanistan, Syria and various African countries, without shelter, proper sanitation or access to food and water.
Authorities said the fire was started by migrants. No one was hurt.
The new temporary tent camp at Kara Tepe, near the island's port of Mytilene, is ready to take in at least 5,000 people.
Officials have said that some of the migrants are reluctant to move to the new camp as they hope to leave the island.
Early on Wednesday, only 1,200 had moved but late in the evening, large groups of migrants carrying their belongings started streaming in.
Government ministers said authorities would continue "for some more days in good faith and communication" to convince the migrants to enter the new camp, saying their transfer would be completed within a few days.
France, Germany and the Netherlands offered to take in hundreds of the camp's residents, including 400 minors, last week.
"As a preliminary step, we are offering to Greece to accept refugees who are minors, other steps must follow," German Chancellor Angela Merkel told a panel discussion in Berlin.
However, Greek Prime Minister Kyriakos Mitsotakis wants that kind of sentiment transformed into action.
"Europe must move from words of solidarity to a policy of acts of solidarity. We have to put the migration crisis at the heart of our discussions and be much more concrete," he said at a summit of Mediterranean leaders in Corsica.