Fighters from the Syrian Democratic Forces are moving closer to the gates of Raqqa, Isis's de-facto capital in Syria, reports say.
The armed groups, made up mostly of Kurds from the YPG and YPJ fighting units, along with Arabs and Christians, are now 20 miles from Raqqa, Sky News reports.
The Syrian Democratic Forces (SDF) have been celebrating a string of victories as they reclaim villages from Isis control.
In the hopes of retaking communities from Isis those suspected of being Isis militants are arrested and men are often taken aside for questioning.
With the help of coalition air strikes, the soldiers advanced from al-Shaddadi to link up with a second group from the SDF, who were attacking from Saluk, near the Turkish border.
The move cut off nearly 4,000 square miles of Isis land.
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Rizgar Serekani, an SDF commander, told Sky News: "We're trying to create a barrier between here and Raqqa, to stop Isis movement and clear the area of all Isis."
Raqqa was captured by Isis forces in August 2014 and has since acted as the group's headquarters in Syria.
Syrian government forces, backed by air strikes, recently took rebel ground around Aleppo and said they were poised to advance on Raqqa.
Independent News Service