A total of 274 undocumented migrants were held across Turkey on Thursday, according to security sources.
The sources, who spoke on condition of anonymity due to restrictions on talking to the media, said 61 migrants were held in eastern Van province, 58 in eastern Erzincan province and 22 in western Kirklareli province.
In another incident in Erzurum, a van carrying 135 undocumented migrants had an accident that left two people dead and several injured, according to Erzurum Governor Seyfettin Azizoglu.
Speaking to reporters, Azizoglu said the injured migrants were taken to hospitals; four of them were said to be in critical condition.
He added the driver of the van was arrested.
Separately, police said in a statement on Thursday said 718 undocumented migrants had been held in western Izmir province during first four months of 2018.
The statement said the migrants were trying to cross into Greece before they were held; 53 suspects were remanded in custody for human smuggling.
It added the number of held undocumented migrants last year for the same period was 140, which marks a significant increase.
Turkey has been a main route for refugees trying to cross into Europe.