Kurds have been fighting against the Islamic State of Iraq and the Levant ISIL) both in both Syria and Iraq.
The armed group the Committees for the Protection of the Kurdish People (YPG) has been trying to stop ISIL from linking its two strongholds, Mosul in Iraq with Raqqa in Syria.
On Monday, the Syrian Kurds had called for help from the air and from the US-led coalition as a matter of urgency.
Al Jazeera's Sue Turton reports from the Syria-Iraq border.
Source: Al Jazeera