By Hanife Erdinc, Sergen Sezgin, Eren Bozkurt, Hakan Mehmet Sahin

CANAKKALE/ADANA/EDIRNE, Turkey

More than 300 irregular migrants have been held across Turkey, security sources said on Friday.

In the northwestern province of Edirne, 170 migrants -- Palestinian, Syrian, Pakistani, Algerian, Afghan, and Moroccan nationals -- were rounded up during regular patrols by gendarmerie units in the village of Bosnakoy and the districts of Ipsala and Meric, said the sources, who asked not to be named due to restrictions on talking to the media.

The migrants were trying to illegally cross the Turkish border, the sources said.

Another gendarmerie unit in the northwestern Canakkale province's Ayvacik district rounded up 41 Afghan nationals.

Some 42 migrants -- among them Syrian nationals -- were held on the Adana-Ceyhan highway near the Adana province.

In Urla district of western Izmir province, 50 migrants were rounded up in Zeytineli Bay upon a tip-off.

Turkey has been a main route for irregular migrants trying to cross into Europe, especially since 2011 when the Syrian civil war began.

Of the migrants held in Turkey last year, 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 migrant flow since 2016. The number was 31,000 in 2016.