Gunmen opened fire on a convoy of Turkish buses inside Syria carrying pilgrims returning from the Hajj pilgrimage in Saudi Arabia early on Monday, wounding two Turks, Turkish media reported.
Reports of the incident were fragmentary and Turkish authorities said they were still trying to establish what had happened. Some of the shaken travellers said the attackers appeared to be Syrian soldiers.
A driver and a pilgrim were hit when the attackers strafed two of the buses driving towards Turkey on the road between the cities of Homs and Hama in western Syria in the early hours of Monday morning, Turkey's state news agency Anatolian said.
Syria has been swept this year by anti-government protests and a harsh crackdown in which thousands have been killed.
Turkey has been vocal in international condemnation of President Bashar al-Assad's repression of the unrest. Thousands of Syrian refugees, including army deserters, have taken refuge in Turkey.
Last week, attacks on Turkish diplomatic missions in Syria by pro-Assad crowds led Ankara to evacuate diplomats' families. After the attacks, Turkey's foreign ministry advised Turkish citizens to avoid non-essential travel to Syria.
On Monday, Cemil Karli, 50, said he had been shot in the stomach and the leg.
We were travelling in a convoy of around eight or nine buses. First a red car appeared and there were four people inside. First they started shooting from there, Anatolian quoted Karli as saying.
When they realised we were going to carry on driving, four other people appeared up ahead and started shooting. Their gunfire did a lot more damage.
Karli said windows in the bus were shattered by bullets and passengers threw themselves on top of each other in the aisle.
This is how we saved our lives. Our bus drove at speed through the armed group and drove without stopping all the way to the Cilvegozu border gate, he said, referring to one of the crossings in Turkey's 910-km (570-mile) border with Syria.
Passengers interviewed by private news agency Dogan said they had been told to get off their bus by up to eight men in Syrian army uniforms at a checkpoint.
GOD SAVED US
They were hidden in their hideouts ... these were soldiers, these were not civilians, their flags were there, one man said.
One of the soldiers said 'come, come', he wanted to get me inside, I didn't go inside.
I had nothing in my hands, there were seven or eight of them. He cocked his gun at me and said 'put your hands up' ... I shouted for everyone to run, we ran and they started firing at our backs. God saved us, he said.
We have returned from death. We have returned from death, said another middle-aged male passenger, sobbing.
Dogan showed television images of a bus with one of its windows smashed, after it had crossed back into Turkey.
A Turkish foreign ministry official said he was aware of an incident and the ministry was trying to establish the details.
Turkish truck drivers interviewed by Reuters said they faced increased hostility when driving through Syria.
Turkish newspapers quoted officials at the weekend saying Turkey could set up a no-fly or buffer zone in Syrian territory to protect people from Assad's security forces, in order to head off a potential exodus of the refugees from Syria.
(Additional reporting by Ece Toksabay, writing by Jonathon Burch; Editing by Andrew Roche)