The migrants, who are Afghan nationals, two children among them, were held in the eastern Erzurum province as they were traveling on the Eastern Express, a dedicated rail line between the capital Ankara and the northeastern province of Kars, an official, who spoke on condition of anonymity due to restrictions on talking to media, said.

They were taken to a repatriation center, the source said.

Separately, in the southeastern Hakkari province, 17 people were arrested on charges of human trafficking.

Turkey has been the main route of refugees trying to cross into Europe, especially since the beginning of the civil war in Syria.

Among the migrants held in 2017 in Turkey, the majority came from Pakistan -- around 15,000 -- followed by Afghans at around 12,000. Syrians totaled about 10,000.

There has been a 60-percent increase in the migrant flow since 2016, when the number was 31,000.