After taking control of territory outside Aleppo city earlier Saturday, the army designated a swathe of Kurdish-held territory in Raqa province southwest of the Euphrates River, including the city of Tabqa, a "closed military zone".

In statements carried on state media, it announced it would target what it said were several military sites in the area -- one of them near Raqa city.

The Syrian army had previously told the Kurdish-led Syrian Democratic Forces (SDF) to evacuate a part of Aleppo province, with SDF leader Mazloum Abdi agreeing on Friday to pull out of the area to positions east of the Euphrates at what he said was the urging of mediators.

But the SDF accused the authorities on Saturday of breaching the deal, saying Kurdish forces in neighbouring Raqa "are currently engaged in intense clashes with factions affiliated with the Damascus government" in an area south of Tabqa, "which was outside the scope of the agreement".

An army statement carried by state media urged the SDF leadership to "immediately fulfil its announced commitments and fully withdraw to the east of the Euphrates River", calling for it to evacuate its fighters from Tabqa.

The army also said it had taken control over Raqa province's Resafa area and several nearby villages.

Raqa province was formerly the Islamic State group's stronghold in Syria before its territorial defeat in a battle spearheaded by the SDF with the support of an international coalition.

The authorities are seeking to extend their control over all of Syria, and the push to retake parts of Aleppo province followed days of clashes in the city of the same name that saw Kurdish fighters cede the last two neighbourhoods they controlled there.