Turkish officials have rounded up nearly 3,000 people in the past four days who were planning to cross the Aegean Sea to Greece, local media reported.
The detentions were part of an operation launched on Monday, a day after Turkey and the European Union reached a deal to stem the flow of refugees into Europe.
The Turkish coastguard apprehended a total of 2,933 people, mainly from Syria and Iraq, as they were preparing to make their way to the Greek island of Lesbos from the north-western town of Ayvacik, in Çanakkale province, and sent them to a detention centre where some could face deportation, Dogan news agency reported.
Thirty-five suspected smugglers were also detained and hundreds of boats were seized, it added.
At a summit in Brussels, the European Union vowed to provide €3bn (£2.2bn) and political concessions to Ankara in return for its cooperation in tackling Europe’s worst refugee crisis since the second world war.
Turkey hosts more than 2 million refugees from the Syrian conflict and is the main launching point for those coming to Europe via Greece.
More than 886,000 refugees and migrants have arrived in Europe by sea this year, according to the latest UN figures. Nearly 600 people have died using the eastern Mediterranean route, according to the International Organisation for Migration.