* Bombs fall metres from Turkish frontier
* Ras al-Ain fell to rebels on Thursday, civilians fled
* Turkey concerned about security on its border with Syria
A Syrian warplane bombed the rebel-held town of Ras al-Ain on Monday, just metres (yards) from the Turkish frontier, sending scores of civilians fleeing for safety into Turkey.
Helicopters also strafed targets near the town, which fell to rebels on Thursday during an advance into Syria's mixed Arab and Kurdish northeast. There was no word on casualties.
The jet struck within metres (yards) of the border fence that divides Ras al-Ain from the Turkish settlement of Ceylanpinar, sending up plumes of black smoke.
A Reuters reporter in Ceylanpinar said the plane flew right along the border and appeared at one point to have entered Turkish airspace.
It was not clear what the bomb struck, but scores of civilians fled the area, scrambling over the fence into Turkey.
To Ankara's alarm, some 9,000 Syrians arrived in one 24-hour period last week, swelling to over 120,000 the number of registered refugees in Turkish camps, with winter setting in.