World Bulletin / News Desk

Civilians have begun fleeing the northern Syrian city of Raqqa, a stronghold of the ISIL terrorist group, amid expectations of an imminent attack by the PYD terrorist group -- with U.S. air support -- aimed at taking the city, local sources told Anadolu Agency.

The PYD is the Syrian affiliate of the PKK terrorist group.

  Thousands of others, the sources said, had begun heading for Syria’s eastern Deir ez-Zour province, most of which is also held by ISIL.

The same local sources said ISIL had begun preparations to counter an anticipated U.S.-led campaign aimed at capturing Raqqa, which is home to an estimated one million people.

Some 4,000 other Raqqa residents have reportedly fled to the ISIL-held village of Halfeti in Aleppo's city of Azaz, located only 6 kilometers (roughly 4 miles) from the Turkish border.

"The number of people fleeing the city can be expected to increase further," the sources said.

On May 4, U.S. Defense Secretary Ashton Carter said a U.S.-led anti-ISIL coalition would provide more firepower and logistic support to its "local partners" to allow them to combat ISIL in Syria’s Raqqa and Iraq’s Mosul.

On Sunday, Gen. Joseph Votel, chief of U.S. Central Command (CENTCOM), paid a surprise visit to Syria.

Brett McGurk, U.S. envoy for the anti-ISIL coalition, tweeted that Votel was "preparing a push on Raqqa".

In a statement, a CENTCOM spokesman said Votel had met with U.S. military advisers working with Syrian Arab fighters and with leaders of the Syrian Democratic Forces (SDF), which includes Kurdish and Arab fighters battling ISIL.

CENTCOM later confirmed that the planned operation to take Raqqa would be led by the SDF.

"We have always been focused on Raqqa and evicting ISIL from the self-declared capital of their so-called ‘caliphate’,” CENTCOM told Anadolu Agency in an emailed statement.

"We will provide support to our partners’ operations as we have previously," it added.