The Kurdish YPG militia captured a town from Islamic State (IS) fighters in northern Syria on 27 July, after a month-long offensive against the ultra-hard-line militants in the area to cut their supply lines, the Syrian Observatory for Human Rights said.
The Observatory said the town of Sarrin, near the Euphrates River, was a launch pad for IS to wage raids on the Kurdish-held town of Kobani, further north at the border with Turkey.
In footage uploaded to the Internet, said to have been filmed in Sarrin on 25 July, Kurdish fighters appear to be engaging and advancing on IS fighters.
"As you know, we have been approaching Sarrin. We besieged Sarrin. Some of them drop their weapons and run away when they see us. They are running away now. We are on top of a hill in Sarrin," said one Kurdish fighter.
"As you know, there was a massacre in [the Turkish town of] Suruc. We will capture Sarrin because of that massacre. We will fight with these gangs and avenge our martyrs. We are coming to the end. They can no longer fight back. They leave dead bodies. Some of them leave their weapons and run away. We came to this point successfully."
US-led air strikes assisted the Kurds in the assault, said the Observatory.
In a second video, believed to have been shot on 24 July, the aftermath of what is said to be coalition air strikes on Sarrin can be seen. The buildings shown have been mostly reduced to rubble.
The YPG, backed by small Syrian rebel groups, has made significant gains against IS in Raqqa province, seizing Tell Abyad at the Turkish border on 15 June before advancing south and capturing the town of Ain Issa.
In July the US-led coalition has conducted some of the most sustained raids in northern Syria against the militants since the campaign began nearly a year ago.