The chief of UN observers in Syria has said their mission is being suspended because of escalating violence in the country.

The head of the UN observers in Syria says that the growing violence is derailing their mission and could prompt the unarmed force to pull out.

At least 28 people have been killed by Syrian government shelling and offensives against rebel-held towns, activists said today.

The UN Secretary General Ban Ki Moon has said increased attacks by government forces on Syrian cities violates the Security Council's demand for an end to hostilities.