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.