Turkey's army has said it has detained almost 800 people trying to cross the border from Syria, including three suspected fighters from the Islamic State of Iraq and Levant (ISIL), after bolstering security in border areas near where the group holds territory.
The military said on Tuesday that 768 people had been detained on Monday while trying to cross the border.
The three suspected ISIL members were sent to jail in the southern city of Sanliurfa after being detained separately on July 2, it said.
Wary of advances by both Syrian Kurdish forces and ISIL in northern Syria, Turkey has sent extra troops and equipment to strengthen parts of its 900km border as the risk of spillovers rises.
Turkey has maintained an open border policy throughout Syria's conflict, absorbing close to two million refugees, but requires legitimate refugees to pass through checkpoints and be documented.
The military did not say why the 768 people had been detained.
Turkey has faced criticism from some Western nations for failing to do more to stop foreign fighters crossing out of the country and joining ISIL.
Ankara argues that domestic intelligence agencies in the West need to stop their nationals being radicalised and travelling to Turkey in the first place.
Turkey has mooted the creation of a 'secure zone' on Syrian soil to prevent a new wave of refugees crossing the border, a strategy which would be likely to require a military incursion, but has made clear it will not act alone and has been lobbying for support from the US-led coalition against ISIL.
Retired General John Allen, appointed by US President Barack Obama to build that coalition, held talks on Tuesday in Ankara with Turkish officials.
While concerned about the threat from ISIL, Turkey also fears the creation of an autonomous Kurdish region in Syria which could further embolden its own 14 million ethnic Kurds.
Prime Minister Ahmet Davutoglu said on Friday there were no immediate plans for any incursion into Syria, but said Turkey would respond if its security were threatened.