The lack of a United Nations Security Council resolution to establish a safe zone in Syria is hampering efforts to help civilians caught up in fighting in the Middle Eastern state, UN relief co-ordinator Baroness Amos said today.
Lady Amos said a resolution would be needed to establish a secure corridor for the delivery of aid supplies or a safe zone for people fleeing violence in the 17-month uprising against president Bashar Assad.
Describing the conditions in the city of Aleppo and other parts of Syria as "extremely worrying", the UN's under-secretary-general for humanitarian affairs said the overriding need was for an effective ceasefire.
But Assad today hailed his army's military action against what he termed "terrorist criminal gangs", saying their battle will determine the fate of the country.
Syrian combat aircraft and artillery last night pounded Aleppo, the country's biggest city, where rebel fighters say troops loyal to Assad have been forced to retreat.
Lady Amos told BBC Radio 4's Today programme: "It is extremely worrying, and it is not just Aleppo. A couple of nights ago we had renewed conflict in parts of Damascus too."
Many people in Aleppo are sheltering in schools, and around 7,000 are believed to be gathered in the city's university, she said. There is also concern that people trying to flee to neighbouring countries are being stopped at roadblocks or targeted by snipers.
"What we need first of all is a ceasefire, which we have not be able to get, so people can be safe," said Lady Amos.
"Without that, some kind of corridor or safe zone of course would be something we could look at if we could make it secure.
"The difficulty is we have no Security Council resolution which would enable that to happen. You don't just get the government forces and the opposition forces to agree - you need to be able to police and secure that corridor or safe zone in some way so that people feel safe to go there and so someone doesn't break that agreement.
"At the moment it is very difficult to see how we can do that."