DAMASCUS - An international task force was to meet Monday in a bid to bolster Syria's fragile ceasefire, as aid workers made the first delivery of desperately needed assistance since the truce began.
The task force, co-chaired by Moscow and Washington, was set to meet from 1400 GMT to evaluate allegations of a range of breaches, according to United Nations special envoy Staffan de Mistura.
At the weekend, key regime backer Russia traded accusations with the main opposition grouping, the High Negotiations Committee, over truce violations.
French Foreign Minister Jean-Marc Ayrault said Monday the allegations "must all of course be verified", and that his government "would be vigilant about (the truce's) concrete application". UN chief Ban Ki-moon said there have been some incidents but the ceasefire was generally holding.
"As of now I can tell you that by and large the cessation of hostilities is holding even though we have experienced some incidents," he told reporters in Geneva on Monday, the truce's third day.
And in an encouraging sign, aid workers began the first aid delivery since the deal came into effect, the Syrian Arab Red Crescent said. Ten trucks carrying blankets and hygiene supplies entered rebel-held Moadamiyet al-Sham, encircled by government forces, and another 41 were to follow on Monday.
UN humanitarian coordinator Yacoub El Hillo said he hoped the relative calm would allow aid to be distributed to 154,000 besieged people over the next five days. Pressure was building to relieve civilians under siege after the UN's human rights chief said thousands could die of hunger.
"The deliberate starvation of people is unequivocally forbidden as a weapon of warfare. By extension, so are sieges," Zeid Ra'ad Al Hussein said, warning that "thousands of people risk starving to death".
The flow of much-needed assistance could also create a more favourable backdrop for peace talks that collapsed in acrimony in early February. UN envoy de Mistura aims to relaunch negotiations on March 7 if the ceasefire lasts and more aid is delivered. The HNC Sunday described the ceasefire as "positive" but lodged a formal complaint with the United Nations and foreign governments about breaches.
"We have violations here and there, but in general it is a lot better than before and people are comfortable," said spokesman Salem al-Meslet. Meslet said the opposition would like to see the truce "last forever", but that the United States was responsible for preventing violations.
An HNC letter to Ban accused the Syrian regime and its allies of committing two dozen truce violations that had killed 29 people and wounded dozens.
The HNC has said it has been kept in the dark about the truce's monitoring mechanism.
The ceasefire does not apply to territory held by the Islamic State group and Al-Qaeda affiliate Al-Nusra Front.
Russia, which has waged a five-month bombing campaign to support President Bashar al-Assad, accused "moderate" rebels and jihadists of nine ceasefire violations.
Kremlin spokesman Dmitry Peskov told reporters the main mechanisms for implementing the truce were now in place. "We knew ahead of time that this would not be easy," he said.
In Aleppo, the Observatory reported some rebel rocket fire on government-held neighbourhoods early on Monday but no casualties.
"Our teachers used to forbid us from going out to the school yard because of the air strikes but today we went out and played," said Ranim, a 10-year-old pupil at a primary school in the rebel-held neighbourhood of Bustan al-Qasr.
The Observatory reported nine Russian air strikes on a town in the central province of Hama early on Monday but had no immediate word on casualties.
It said seven civilians were killed in Russian strikes on Sunday on a town in Aleppo province where Al-Nusra has a presence.
Washington urged patience from all sides to give the truce a chance to firm up. "Setbacks are inevitable," a senior US administration official said. "Even under the best of circumstances, we don't expect the violence to end immediately. In fact, we are certain that there will continue to be fighting, in part because of organisations like ISIL (Islamic State) and Al-Nusra."
There has been no let-up in the US-led air campaign targeting IS since the truce went into effect.
The coalition said that on Sunday it carried out 12 strikes against the jihadists in Syria, four of them around the town of Tal Abyad on the Turkish border where IS has been trying to regain territory from US-backed Kurdish forces.