Syrian opposition demands urgent international action over Aleppo carnage

The head of the Syrian opposition's top negotiations body demanded on Tuesday an emergency UN Security Council session to discuss the escalating crisis in Aleppo.

In a letter addressed to the UN secretary general, Riad Hijab urged Ban Ki Moon to hold "an emergency meeting on the situation in Aleppo" calling on UN member states to protect civilians through concrete actions aimed at halting "indiscriminate air raids across Syria as well as the deliberate targeting of medical facilities and personnel."

Hijab stressed the need to "ensure the delivery of humanitarian aid to the residents of Aleppo and across Syria," demanding the "UN end the blockade imposed by regime forces in Aleppo and other parts of the country."

The opposition leader also demanded those responsible for the deadly raids be held accountable for war crimes against the Syrian people.

Earlier on Tuesday, government troops seized a rebel-held neighbourhood on the northwest outskirts of Aleppo, tightening their siege of the opposition-held parts of the city, a monitoring group said.

Up to 300,000 Syrians could be trapped in eastern Aleppo, as the Syrian regime now controls Castello Road

Aleppo has been roughly divided between government control in the west and rebel control in the east since mid-2012.

In recent weeks, however, regime advances around the city's outskirts have severed the only remaining route into the rebel-held eastern neighbourhoods, effectively trapping hundreds of thousands of people under siege.

Opposition forces have responded by firing barrages of missiles into government districts, reportedly killing scores of civilians. 

The Syrian Network for Human Rights emphasised that 300,000 Syrians remain trapped in eastern Aleppo, as the Syrian regime now controls Castello Road. 

In a report issued on Tuesday, it said Syria's opposition forces also contributed to the siege by tightly controlling the Sheikh Maksoud neighbourhood and refusing to facilitate the passage of civilians and aid. 

The report said that serious violations of international and humanitarian law had taken place since the road was taken, saying that around 99 civilians had been killed since the start of the siege to 23 July. 

Analysts estimate that around 400,000 people have been killed in Syria since the conflict began in March 2011 with anti-government protests that were met by a regime crackdown.