A new ceasefire in Syria has brought a full day with no combat deaths in the war between Syrian President Bashar al-Assad and his opponents. Meanwhile, efforts to deliver aid to besieged areas cautiously got under way.

With the sun setting on Damascus, the first full day of a much anticipated ceasefire here in Syria is coming to an end. And despite the long odds many give for its success, the deal is largely holding so far.

24 hours in - there have been no civilian casualties reported - according to monitoring groups. But this doesn't mean the day went without incident.

On the contrary, shortly after dawn on Tuesday the Syrian Army said its air defenses shot down an Israeli fighter jet and a drone in two separate locations over southwest Syria -- but the Israeli Ministry of Defense denied the reports - saying all its aircraft are accounted for.

Israel, which is not a party to the new ceasefire - has conducted several air raids on Syrian positions in recent weeks - in response to what it says were stray shells from Syria that crossed into the Israeli-occupied Golan Heights area.

As for humanitarian efforts -- the Syrian ministry of foreign affairs issued a statement saying it will not allow aid, particularly from the Turkish government, to be delivered to besieged Aleppo without prior co-ordination with it and the UN. 

Sources in Aleppo province tell CCTV that the Syrian army redeployed units around  Castello road to allow the flow of aid into rebel held eastern Aleppo and that Russian monitors were seen heading to the area to set up shop there.

UN coordinators say they are preparing to bring desperately needed food and medicine to the tens of thousands of people in need in Aleppo - but that they must be assured of peace - before convoys set out.