Fighting rages in Aleppo

Rebels put up fierce resistance yesterday in a key district of Syria's battered Aleppo, where a regime offensive has left bodies in the streets and sparked a global outcry.

The government assault on the northern city has spurred a mass exodus of tens of thousands of residents from the opposition-held east and prompted fresh calls by Russia for aid corridors.

President Bashar al-Assad's forces captured the city's northeast this week and were focused on seizing Sheikh Saeed, a large district on the city's southeast edges.

But anti-government fighters put up a strong defence there overnight, rolling back recent government gains, according to the Syrian Observatory for Human Rights.

"The regime and allied fighters... wanted to take this neighbourhood at any cost, because capturing it would allow them to target all remaining rebel-held districts," said Observatory head Rami Abdel Rahman.

"But rebels put up ferocious resistance, because they knew they would be trapped if Sheikh Saeed fell," Abdel Rahman added.

The head of the Britain-based monitor said opposition forces were now once again in control of at least 70 percent of the neighbourhood.

Sheikh Saeed borders the last remaining sections of Aleppo still in rebel hands -- a collection of densely populated residential neighbourhoods where thousands have sought refuge from advancing regime forces.

In preparation for street-by-street fighting in these districts, hundreds of fighters from Syria's elite Republican Guard and Fourth Division arrived in Aleppo yesterday, according to the Observatory.

More than 300 civilians, including dozens of children, have been killed in east Aleppo since the government began its offensive on November 15, according to the Observatory.

Retaliatory rocket fire by the rebels on government-held western areas of the city has killed 55 civilians, the monitor says.

According to Syrian state news agency SANA, one civilian was killed and three were wounded yesterday in rebel rocket attacks.

An AFP correspondent could hear steady rocket fire on west Aleppo overnight and into yesterday morning.

Intermittent clashes yesterday rocked a block of residential buildings on the city's eastern edges, where advancing regime forces have sought to secure the road leading towards Aleppo's airport.

The escalation of violence in Aleppo has been met with international outrage, including a warning by the UN that the city's east could become "a giant graveyard."

Russia on Thursday proposed setting up four humanitarian corridors into east Aleppo to bring in aid and evacuated severely wounded people.

Moscow has announced several humanitarian pauses in Aleppo to allow civilians to flee, but until the recent military escalation, only a handful did so.

Its support for Assad, including launching a bombing campaign in support of his forces in September 2015, means many residents of east Aleppo have been wary of such offers in the past.

Since Saturday more than 50,000 people have poured out of east Aleppo into territory controlled by government forces or local Kurdish authorities, according to the Observatory.

Many are transported to temporary shelters outside the city, where they register with Syrian authorities to receive food, blankets, and mattresses.