Turkey troops use tear gas to clear Syria border Kurds
Turkish security forces have fired water cannon and tear gas at crowds which had gathered in support of Syrian Kurdish refugees on the border.
Police said they wanted to stop Kurdish fighters entering Syria, the Associated Press reported, while local TV said Kurds had been trying to deliver aid.
It comes after some 66,000 refugees poured into Turkey in 24 hours.
Turkey opened its border on Friday to Syrians fleeing the town of Kobane in fear of an Islamic State attack.
Reuters news agency said troops cleared about 2,000 people from the border area south of the Turkish town of Suruc on Sunday morning. Some of them threw stones at the security forces, though there were no immediate reports of injuries, the agency said.
Turkey has taken in more than 847,000 refugees since the uprising against Syrian President Bashar al-Assad began three years ago.
The UN refugee agency UNHCR says it is boosting relief efforts as hundreds of thousands more could cross the border.
It said Kobane had been relatively safe for much of the Syrian conflict and as many as 200,000 internally displaced people had found refuge there.
IS controls large areas of Syria and Iraq, and has seized dozens of villages around Kobane, also called Ayn al-Arab.
The capture of the town would give IS control of a large strip of Syria's northern border with Turkey.
Analysis: Mark Lowen, BBC News, on the Turkish-Syrian border
The influx is astonishing - and still continues.
At least 66,000 Syrian Kurds have entered Turkey since Friday, when the country opened parts of its border crossing with Syria.
Around 300 Kurdish fighters are said to have gone the other way, crossing from Turkey into Syria to help resist the IS onslaught.
Until recently, Turks and Kurds fought a civil war that killed 40,000 people. The fact that Turkey is now accepting tens of thousands of Kurdish refugees is a sign of how the rise of Islamic State is shifting allegiances in this region.
Reports said IS had advanced to within about 10km (six miles) of Kobane by Sunday morning.
A resident of the town told AFP news agency most of the women and children of Kobane had left, and that only thousands of armed Kurdish men remained, ready to defend the town.
He warned though that the fighters would be outgunned by IS heavy weapons and appealed to the US to launch air strikes on IS positions there.
The US has said it will attack the group in Syria as part of a strategy to destroy it, though so far it has carried out air strikes against IS only in Iraq.
Attacking IS in Syria is considered more complicated, partly because of the strength of the country's air defence system and because foreign air strikes do not have the approval of Bashar al-Assad.
- Formed out of al-Qaeda in Iraq (AQI) in 2013, IS first captured Raqqa in eastern Syria
- It captured broad swathes of Iraq in June, including Mosul, and declared a "caliphate" in areas it controls in Syria and Iraq
- Pursuing an extreme form of Sunni Islam, IS has persecuted non-Muslims such as Yazidis and Christians, as well as Shia Muslims, whom it regards as heretics
- Known for its brutal tactics, including beheadings of soldiers, Western journalists and aid workers
- The CIA says the group could have as many as 31,000 fighters in Iraq and Syria
- The US has been launching air strikes on IS targets in north-eastern Iraq since mid-August