Turkish security forces on Sunday detained an American journalist and two Syrians as they tried to cross a river flowing from Syria into southern Turkey by raft, the army said.
The three were spotted on the Asi river near the border province of Hatay, the army said in a statement, without revealing their identities.
The journalist, said to be 60 years old, was taken to a police station for questioning and then flown to Istanbul for deportation, Hurriyet newspaper reported on its website.
Nothing was immediately known about the fate of the Syrians.
The army said in a separate statement that six Turkish F-16 jets performing air patrolling duties on the border had come under a radar lock by Syrian air missile batteries for 2.5 minutes.
Turkey, a staunch opponent of the Damascus regime, hosts about one million refugees from the three-year-old Syrian conflict, many of them in camps along the border.
But its open-door policy enables refugees, rebels and smugglers to cross the border easily, creating a huge security challenge for Turkey.
In its latest attempt to prevent illegal crossings and smuggling, Turkey started on Friday to raise a portable concrete wall in the town of Reyhanli in Hatay, which hosts many Syrian refugees.