Air strikes hit the only road into rebel-held areas of Aleppo city on Sunday in the heaviest bombing since February, a rebel official and monitors said, jeopardising access for 300,000 Syrians.
Russian warplanes carried out the attacks on the Castello road, which was still open but dangerous, the official and monitors said. Defence officials from Syria's government and its ally Russia could not immediately be reached for comment.
The Syrian Observatory for Human Rights group said the road was hit in a week of escalating air strikes, with Sunday's attack the most intense yet.
The city of Aleppo, about 50km south of the Turkish border, is divided between the government and rebels fighting to topple Syrian President Bashar Al Assad.
A truce was brokered by the United States and Russia in February. But the agreement has since unravelled, with fighting and bombardment in Aleppo playing a big part in its collapse.
Kurdish-led YPG forces, which control the Sheikh Maqsoud area in Aleppo that overlooks the Castello road and are tacitly aligned with the government, have also disrupted the road with snipers who target civilians using the road that is a lifeline for the city to the countryside.
Mainstream Syrian rebel groups said on Sunday they would no longer abide by the UN truce deal unless the Syrian army ended a major assault on their positions in the suburbs of Damascus within 48 hours.
A statement by the Free Syrian Army (FSA) signed by nearly 40 rebel groups that operate across Syria said they would deem the cessation of hostilities deal as having ‘totally collapsed’ if the assault by Syrian government and allied Lebanese Hezbollah forces fighters did not cease within two days.
The signatories, who include Western- and Turkish-backed groups operating on the main frontlines in northern and southern Syria, said once the two-day period had ended, rebels would respond with ‘all the legitimate means to defend the civilians living in these areas’.
In their joint statement, the rebels said the continued attacks by the army on the besieged rebel-held areas around Damascus and their strongholds in Aleppo city and Idlib province were putting peace-making efforts at risk.
The Syrian army stopped extending the cessation of hostilities this month after accusing rebels of violating the agreement by firing at government-controlled residential areas.For all the latest business news from the UAE and Gulf countries, follow us on Twitter and Linkedin, like us on Facebook and subscribe to our YouTube page, which is updated daily.