BEIRUT – Fierce fighting in a border town in northeastern Syrian sent about 8,000 people fleeing into neighboring Turkey over a 24-hour period, one of the largest single-day surges of refugees since the Syrian conflict began, officials said Friday.

Driving the sudden exodus that began Thursday was intense fighting in the northeastern Syrian border city of Ras Ayn, where rebels were reported to have seized security compounds and occupied much of the town. Panicked civilians fled en masse, dodging gunfire and shelling and in some cases struggling to get through barbed-wire fences along the frontier.

The situation dramatized again how Syria’s spiraling internal conflict is spilling over its borders, threatening to destabilize neighboring nations whose leaders are alarmed at the upheaval next door.

Overall, about 11,000 refugees poured out of Syria in a 24-hour period beginning Thursday, the United Nations said Friday.

Most were trying to escape the fighting in Ras Ayn. But another 1,000 fled into Turkey because of violence further west, in Syria’s Idlib province, and 2,000 crossed into Jordan and Lebanon, the U.N. said.

Turkey now has more than 120,000 Syrian refugees, well beyond the 100,000 total that Ankara had said would be its limit.

“How far will this go?” asked a frustrated Turkish Prime Minister Recep Tayyip Erdogan, who was on a trip to Indonesia. His comments were reported on the website of the Turkish newspaper Today’s Zaman.

Turkish officials have lobbied, without success, for the establishment of an internationally protected buffer zone inside Syria where war refugees could find a haven. But the United States and other nations are hesitant to make the military commitment that would be essential to secure protected territory.

Meanwhile, in the Gulf nation of Qatar, Syria’s best-known opposition group, the Syrian National Council, said it had elected veteran Christian dissident George Sabra as its president. The umbrella group – which critics say is dominated by the Islamist Muslim Brotherhood – is struggling to show it is representative of Syria’s minority communities, including Christians, Kurds and Alawites, the Shiite sect that includes President Bashar Assad.