BBC News with Iain Purdon

The United Nations Secretary General Ban Ki-moon says the Syrian authorities have committed clear and widespread crimes against the country's civilian population. He was addressing the UN General Assembly in New York. Earlier, the International Committee of the Red Cross said its aid convoy in the devastated city of Homs had been denied access to the devastated Baba Amr district. Mr Ban said there were grisly reports coming out of Syria.

"In Homs, Hama and elsewhere, the brutal fighting has trapped civilians in their homes without food, heat or electricity or medical care, without any chance of evacuating the wounded or burying the dead. People have been reduced to melting snow for drinking water. This atrocious assault is all the more appalling for having been waged by the government itself, systematically attacking its own people."