Tal Abyad, the strategic town close to the Turkish border, is a major loss for "Islamic State" militants as they can no longer use the route to bring in fighters and ammunition.
Kurdish fighters are in "full control" of the Syrian border town of Tal Abyad, said The Syrian Observatory for Human Rights on Tuesday.
"Since dawn this morning, not a single bullet has been fired, the monitoring group's director Rami Abdel Rahman told the AFP news agency. The victory was also confirmed by leader of the Kurdish People's Protection Units (YPG) Ploate Can on social media.
Together with Syrian rebel forces, the YPG seized the strategic town from 'Islamic State' militants a day earlier, cutting off a vital supply route from Turkey.
The jihadist group had been using Tal Abyad to send fighters and ammunition to its de facto capital Raqqa to the south. The town was also used to smuggle out black market oil, according to reports.
At least 40 jihadists were killed in US-led airstrikes while dozens of others fled to other IS-controlled areas, monitors said.
Trail of destruction
Abdel Rahman described how YPG fighters were combing the town for mines and booby-trapped cars before civilians could return.
The jihadists blew up bridges southeast and southwest of Tal Abyad to prevent the Kurdish militia and Syrian rebels from pushing forward, he added.
The capture of the town is a major coup for the Syrian Kurds after they liberated Kobane, another border town in January following months of battles.
Sunni militant organization IS has captured vast swathes of territory in Syria and Iraq but have been somewhat thwarted in their advance by US-led air power.
Fearing a major battle around Tal Abyad over the past few days, Kurdish and Arab civilians clamored behind barbed wire at the border before eventually being allowed to cross into Turkey.
But the Kurds' success has been criticized by Turkey which says it has seen signs of ethnic cleansing by both Kurdish and Islamic militant groups in northern Syria.
The capture of Tel Abyad means the Syrian Kurds effectively control some 400 kilometers of the border with Turkey which leaves Ankara uneasy because of historic violence by ethnic Kurdish PKK rebels in Turkey.
Turkish President Recep Tayyip Erdogan has accused the West of backing what it describes as "Kurdish terrorists" in the fight against IS which could eventually threaten Turkey's border.
mm/jil (AFP, DPA)