Either 'death or surrender'

Syria's army pushed forward in Aleppo yesterday as thousands fled rebel-held areas but its forces lost ground to the south where the Islamic State group recaptured the ancient city of Palmyra.

After a sudden withdrawal by regime forces, IS jihadists made a lightning-fast advance across Palmyra, sparking new worries for its remaining ancient treasures.

Forces loyal to President Bashar al-Assad have been focused since mid-November on second city Aleppo, where they have retaken about 85 percent of the one-time rebel bastion in the city's east.

Rebels now control only a small area of Aleppo that is full of civilians and under very fierce bombardment after pro-government forces took the al-Maadi district, a Turkey-based official with the Jabha Shamiya rebel group said yesterday.

Rebel groups in Aleppo had received no word about US-Russia talks to resolve the crisis in Aleppo, the official said, warning that it would end "in a tragic way" without outside intervention and that they faced "death or surrender".

The Syrian Observatory for Human Rights said more than 10,000 people had fled the remaining rebel-held districts since midnight, heading to government-run west Aleppo and newly retaken areas in the city's north and centre.

An estimated 120,000 people have poured out of east Aleppo since late November, according to the Britain-based monitor. State news agency SANA said at least 4,000 people had fled rebel districts in just hours yesterday and were taken by bus to temporary shelters.

US and Russian officials were expected to continue talks in Geneva Sunday on trying to reach a ceasefire in Aleppo, but a week of intense diplomatic efforts have failed to stem the fighting.

At least 413 civilians have been killed in east Aleppo since the November 15 start of the offensive, according to the Observatory, and 139 killed in rebel rocket fire on the city's west.

Meanwhile, US Defence Secretary Ashton Carter held talks in Baghdad yesterday to discuss the coming stages of the offensive to retake the city of Mosul from the Islamic State jihadist group.

Carter flew to the Iraqi capital on an announced visit to "survey key locations directly supporting the battle for Mosul", the Pentagon said in a statement.

Around 5,000 US troops are deployed in Iraq as part of an "advise and assist" mission to support Iraqi federal and Kurdish peshmerga forces battling jihadists.