The United Nations is blaming Iran for supplying the Syrian army with weapons. The UN says it has found evidence Iran been organising illegal shipments.

Meanwhile, both Russia and the US acknowledge that they are helping the two sides in Syria's internal conflict as well.

The implications of this are profound: not only are the two sides on the ground ignoring the terms of the ceasefire, but it also seems that foreign countries - which on paper signed up to the Annan plan and its spirit of demilitarisation - are, in practice and in different ways, both offering supplies which undermine it.

Iran would say that makes criticism of it sound a bit hollow. And it also reinforces the idea that Syria has turned into a proxy conflict between Russia on one side, and the self-titled Friends of Syria on the other.

Laurence Lee reports.