Thousands of Syrian migrants have until Tuesday to leave Istanbul or face expulsion from Turkey's biggest city.
Authorities have told unregistered migrants to return to the province they are registered in, as part of a bid to relieve pressure on the city.But some Syrians told the BBC many were being deported to Idlib, inside Syria, where fighting is escalating.
They say many are being forced to sign voluntary return documents that they cannot read or understand.
The order to relocate was issued in late July, giving those affected about a month to comply.
Since Syria's civil war began over eight years ago, some 3.6 million Syrians have fled north to neighbouring Turkey, the BBC's Mark Lowen reports.
About half a million are registered in Istanbul - but estimates suggest twice that number are living there, having travelled from the provinces they were first registered in.