Syria's fragile ceasefire entered its second day on Sunday, with battlezones across the war-scarred country largely quiet for the first time in five years despite some sporadic breaches.
The temporary truce, brokered by Washington and Moscow, is seen as a crucial step towards ending a conflict that has claimed 270,000 lives and displaced more than half the population.
It survived a shaky first day, during which state media said shells were fired on the capital while rebels also accused government forces of "violations".
"I think this is the first time we've woken up without the sound of shelling," said Ammar al-Rai, a 22-year-old medical student in Damascus.
An international task force set up to monitor the fighting co-chaired by the United States and Russia said Saturday had been largely successful.
"The United Nations, the United States and Russia have made a positive assessment of the first hours of the cessation of hostilities," a Western diplomat said after a meeting of the International Syria Support Group in Geneva.
The UN reported "some incidents" in apparent violation of the truce, but "they have been defused", he said.
Russian Foreign Minister Sergei Lavrov's office said he and US Secretary of State John Kerry had "hailed" the ceasefire in a phone call, and discussed ways of improving cooperation between their militaries.
UN envoy Staffan de Mistura has said peace talks will resume on March 7 if the ceasefire prevails and more aid is delivered -- a key sticking point in negotiations.
A spokesman for the UN's humanitarian affairs office said the next convoys are expected to leave on Sunday, after aid reached tens of thousands of people in besieged cities over the past week.
"If it (the truce) holds, it will create the conditions for full, sustained and unimpeded humanitarian access throughout Syria," said EU foreign policy chief Federica Mogherini.
The ceasefire faces formidable challenges, however, particularly as it excludes the powerful Islamic State (IS) militant group and Al-Qaeda's Syria affiliate Al-Nusra Front.
Russia, which has waged nearly five months of intense air strikes in support of Syrian President Bashar al-Assad, said it had halted bombing in all areas covered by the truce.
Moscow has vowed to keep striking IS, Al-Nusra and other "terrorist groups", but said it grounded its warplanes in the Syria campaign on the first day of the truce to avoid potential "mistakes".
Among the ceasefire breaches, state media said "terrorist groups" fired shells on Damascus, but caused no casualties. Rebels also accused government forces of intermittent "truce violations".
In second city Aleppo, two people were killed and four wounded when shells hit the majority-Kurdish neighbourhood of Sheikh Maqsud, the Britain-based Syrian Observatory for Human Rights monitor said.
State media said one person was killed by sniper fire in the same district.
The city is now almost completely encircled by pro-regime troops after a massive Russian-backed offensive that has caused tens of thousands to flee.
On Saturday, however, locals came out to enjoy the calm and children played in parks.
"I hope the truce continues even for a limited time so we can get back part of our old lives from before the war," said Abu Nadim, a father of four.
Islamist militants attacked the border town of Tal Abyad in Raqa province, sparking clashes that killed at least 70 IS members, 20 Kurdish militiamen and two civilians, the Observatory said.
US-led coalition warplanes launched at least 10 air strikes against the Islamist militants, it reported.
Twin suicide bombings meanwhile killed six people outside the town of Salamiyeh in Hama province, where IS is present, state news agency SANA said.
The complexities of a conflict which escalated from anti-government protests into a full-blown war drawing in rival world powers make brokering a lasting ceasefire a major challenge.
Assad has been bolstered by support from Russia and Iran while the West, Turkey and Gulf states back rebel groups.
"The pressure being placed by Russia and the US on regional actors is such that many of these regional actors can't reject the political process entirely," said Firas Abi Ali, an analyst for IHS Country Risk in London.
"This is putting them in a bind where they're compelled to behave as if they're part of the process, regardless of what they actually want from it."
Syria's top opposition grouping, the High Negotiations Committee, said Friday that 97 opposition factions had agreed to respect the truce, for two weeks initially.
A commander in the hardline Islamist faction Ahrar al-Sham said his group -- allied with Al-Nusra -- had not conducted any military operations since the truce started.
"But the ceasefire is stillborn, because it began with violations from the regime. It will be very difficult for the ceasefire to hold," Hussam Salameh warned.