Two men hijacked a plane heading for Istanbul from northern Cyprus on Saturday, but gave themselves up and released their hostages after forcing the plane to land in southern Turkey.
Turkish Interior Minister Osman Gunes said one hijacker was Turkish and the other had a Syrian passport but could be Palestinian. Their motives were being investigated.
"One of them apparently apologised to the Turkish people," Gunes told reporters after the five-hour drama came to an end.
Fifteen minutes after take-off one of the hijackers tried to force the cock-pit door open and told passengers he was a member of al Qaeda, Governor Alaaddin Yuksel said. Police also arrested a passenger suspected of being linked to the hijackers, he said.
Civil Aviation chief Ali Ariduru told reporters there was no clear information on witness claims that the hijackers had a bomb, but it appeared they had a knife.
The plane was hijacked as it brought 136 passengers from northern Cyprus — a destination popular with Turkish and foreign tourists — to Istanbul. CEO of Atlas Jet airline Tuncay Doganer said the plane was forced to land as it did not have enough fuel to get to Tehran as the hijackers demanded.
Most of the passengers were released or broke out through emergency exits. TV footage showed passengers running along the wings and jumping down onto the tarmac.
The pilots also escaped but four passengers and two crew members were held hostage as negotiations took place.
Hijackings are not uncommon in Turkey, where a number of radical groups ranging from Kurdish separatists to far-left militants operate, and several incidents in the last year or so have ended without casualties.
But the peak holiday season hijacking could be bad news for Turkey's large foreign currency-earning tourism sector, which is picking up this year after a bad 2006, when regional instability and a separatist bombing campaign hurt the industry.
Cyprus, also a major tourist destination, is divided between the internationally recognised government in the south and an enclave in the north recognised only by Ankara.