The Turkish authorities today reported that 643 suspected members of the Islamic State were arrested since the beginning of the month while illegally attempting to enter the country.
During the same time period, 496 were reportedly arrested attempting to enter Syria from Turkey.
The Turkish authorities stressed the significant increase in numbers of IS who have been arrested in recent months, with arrests of suspected militants crossing the border said to have more than tripled since January.
Over the past year Turkey has been told by its Western allies to urgently step up efforts to stop the flow of extremists across its borders to and from Syria.
After a string of deadly attacks inside Turkey blamed on IS in recent months, Ankara has intensified efforts to improve border security, with the army reporting the capture of IS militants almost daily.
The US has offered Turkey technology to block the Islamic State group at the Syrian border and have spent months discussing ways to fortify the 98-km-long stretch of land, the last piece of unsecured border between Syria and Turkey.
So far Turkey has deployed 25,000 additional soldiers and installed concrete barriers and fences along the border, but this has reportedly not been enough to secure it, with IS carrying out attacks in Turkish territory.