Greek security forces on Wednesday allegedly left 29 undocumented migrants stranded at the Turkish side of Meric River, which flows between the two countries and through the Balkans.
The migrants were detained and kept in overnight custody in Greece on Tuesday.
Turkish border forces found the migrants stuck near Serem Island in the river.
All of them were rescued, and two, who were in critical condition, were admitted to a local hospital.
The migrants were from Iran, Bangladesh, Afghanistan, Pakistan, Syria, Palestine and Algeria.
"The police detained us. We waited there for a while. They took us to the other [Turkish] side in military boats," Mustafa Bilkasim, a 25-year-old Libyan migrant told Anadolu Agency.
Bilkasim said he wanted to reunite with his family in Europe.
Kasim Emin, a 27-year-old Palestinian, complained of maltreatment by the Greek police.
"We were jailed. It was awful. We were beaten up by armed men in uniform. They took away our cell phones, and we stayed out in the snowfall for almost 13 hours," he said.
Meric River has been a main route for illegal migrants to cross into Europe since Syria's civil war erupted in 2011.
