ANKARA (Reuters) - Turkey said it had detained a "main perpetrator" of the bombings that killed 51 people near the Syrian border last month, adding that the Turkish man had been caught as he tried to flee over the frontier.
Turkey has accused Syria of involvement in the twin attacks in the border town of Reyhanli on May 11, but Damascus has denied any role.
The provincial governor's office in Hatay Province where Reyhanli is located, said on Tuesday it had detained one of the bombers as he tried to cross into Syria.
"On Monday June 10 at around 23:00, an individual with the initials N.E., who is considered to be one of the main perpetrators of the bombing incidents ... was caught near the border in our province's Yayladagi district," it said.
Police had been searching for the man. Last month, police detained more than 15 people in relation to the bombings, including another alleged "perpetrator". Four people have been charged.
Government ministers have said the bombings - among the deadliest attacks in Turkey's modern history - were carried out by a group with ties to the government of Syrian President Bashar al-Assad.
In the early hours of Tuesday, the Turkish military said its troops had fired warning shots into the air to prevent a group of around 1,000 people from crossing illegally into Turkey from Syria.
A Turkish official said armed fuel smugglers who often used the cover of refugees had stepped up their operations along the border in recent weeks.
The official denied Ankara was deliberately preventing refugees from entering Turkey, saying they were still being allowed through official crossings under the control of Syrian rebels trying to overthrow Assad.
Incidents between Turkish troops and Syrian smugglers and refugees along the border have intensified in the last 10 days.
Ankara has stepped up security at crossings and along the 910-km (560-mile) shared frontier since the bombings.
Some 400,000 Syrian refugees have fled fighting in their homeland to Turkey, with around 1,000 people crossing every day, according to officials.
Border incidents have heightened fears that Syria's civil war is dragging in neighboring states. Turkish troops have fired into Syria more than once this month after coming under fire from gunmen on the other side.
(Writing by Jonathon Burch; Editing by Humeyra Pamuk and Andrew Roche)