The move raises fresh concerns of further fighting between the two sides, as Syria's Islamist government seeks to extend its authority across the country and progress stalls on integrating the Kurds' de facto autonomous administration and forces into the central government.

In Qamishli, the main Kurdish city in the country's northeast, thousands of people demonstrated against the Aleppo violence, some burning pictures of Syrian President Ahmed al-Sharaa, an AFP correspondent said.

Syrian state television published an army statement with a map declaring a large area east of Aleppo city a "closed military zone" and said "all armed groups in this area must withdraw to east of the Euphrates" River.

The area begins near Deir Hafer, around 50 kilometres (30 miles) east of Aleppo and extends to the Euphrates further east, as well as towards the south.

On Monday, Syria accused the US-backed, Kurdish-led Syrian Democratic Forces of sending reinforcements to Deir Hafer and said it sent its own personnel there in response.

The SDF is the de facto army of the Kurds' semi-autonomous administration and controls swathes of the country's oil-rich north and northeast, much of which it captured during Syria's civil war and the fight against the Islamic State group.

An AFP correspondent saw government forces transporting military reinforcements including air defence batteries and artillery towards Deir Hafer on Tuesday.

The SDF denied any build-up of its personnel around Deir Hafer.

- 'Bloodshed' -

Syria's government took full control of Aleppo city over the weekend after taking over its Kurdish-majority Sheikh Maqsud and Ashrafiyeh neighbourhoods and evacuating fighters to Kurdish-controlled areas in the country's northeast.

Both sides have traded blame over who started the violence last Tuesday that killed dozens and displaced tens of thousands of people.

In Qamishli, thousands of people protested against the Aleppo violence and Syrian leader Sharaa, some carrying Kurdish flags or banners in support of the SDF and its chief Mazloum Abdi.

"Leave, Jolani!" they shouted, referring to Sharaa by his nom de guerre as a former Islamist rebel commander, Abu Mohammed al-Jolani.

"This government has not honoured its commitments towards any Syrians," said cafe owner Joudi Ali.

"There has been bloodshed since it took power, like the Alawite and Druze massacres," the 29-year-old told AFP, referring to sectarian violence last year involving the two minority communities.

Most shops were shut in Qamishli as residents adhered to a general strike.

Other protesters burned portraits of Turkish Foreign Minister Hakan Fidan, whose country has lauded the Syrian government's Aleppo operation "against terrorist organisations".

- PKK, Turkey -

Turkey has long been hostile to the SDF, seeing it as an extension of the Kurdistan Workers' Party (PKK) and a major threat along its southern border.

Last year, the PKK announced an end to its armed struggle against the Turkish state and began destroying its weapons, but Ankara has insisted that the move include armed Kurdish groups in Syria.

On Tuesday, the PKK called the "attack on the Kurdish neighbourhoods in Aleppo" an attempt to sabotage peace moves between it and Ankara.

A day earlier, Ankara's ruling party called the clashes an attempt by Kurdish fighters to sabotage the efforts.

Turkey has repeatedly called for the Syrian Kurdish forces' integration into the new government as part of a March deal between Damascus and the SDF that was supposed to have been implemented last year.

The Britain-based Syrian Observatory for Human Rights reported 45 civilians and 60 soldiers and fighters were killed from both sides in the Aleppo violence.

Neither side has released a comprehensive toll.

Aleppo civil defence official Faysal Mohammad told AFP on Tuesday that emergency workers had pulled 50 bodies from the two Kurdish-majority neighbourhoods since the end of fighting, without saying whether they were combatants or civilians.

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