Syria truce hangs in the balance amid attacks and lack of aid

Syria's week-long ceasefire, brokered by the United States and Russia, is in doubt amid repeated violations and with no aid deliveries to the besieged rebel-held part of the northern city of Aleppo, a key point in the agreement.

The uncertainty cast doubts on a US-Russian plan to set up a coordination centre that would plan strikes against militants in the country.