The number of Syrian refugees in Turkey has exceeded 600,000 and more than 400,000 of them are living outside the refugee camps set up mainly in Turkish border cities, the Turkish disaster management agency has said.
"We conducted a study before the Eid (al-Adha) holidays and the numbers have increased above 600,000," said Mustafa Aydogdu, spokesman for the Disaster and Emergency Management Directorate(AFAD).
Turkey, which shares a 900km border with Syria, is a strong critic of Syrian President Bashar al-Assad.
It is the and a main supporter of the rebels fighting against him.
It has said it will maintain its "open door" policy to those fleeing the Syrian civil war, now in its third year.
It has closed border crossings from time to time following clashes near the frontier.
About 200,000 Syrians were living in 21 refugee camps, mainly near cities near the border, Mr Aydogdu said, while the rest chose to live in rented accommodation outside the camps.
Prime Minister Tayyip Erdogan said in August Turkey has already spent around $2bn (€1.4bn) sheltering the refugees.
The United Nations expects another two million Syrians to become refugees in 2014 and millions more to be displaced within the country.
Elsewhere, one of the most senior rebel commanders in southern Syria was killed during clashes with government troops near the city of Deraa.
Yasser al-Aboud, a former Syrian army officer who defected in the early days of the revolt to join the Free Syrian Army, was leading an assault on army checkpoints in the town of Tafas, northwest of Deraa, they added.
Allies said he had planned some of the rebels' main assaults on government positions in recent months.
Meanwhile, Syrian President Bashar al-Assad,who is fighting a 2-1/2-year revolt against his rule has said he saw no reason he could not run for the 2014 presidential elections.
He said: "Personally, I don't see any obstacles to being nominated to run in the next presidential elections," the news channel quoted him as saying in an interview.