A cessation of hostilities in Syria's civil war largely held on Saturday, providing respite to some of the 12 million homeless residents of that country ahead of the fifth anniversary of the start of the conflict.

Embattled Syrian president Bashar Assad and his Russian and Iranian benefactors agreed to the truce on Friday by a pre-set deadline of noon local time. So, too, did a commission representing roughly 94 armed rebel groups fighting for Assad's ouster.

Several violations of the informal agreement were reported by rebel groups over the course of its first 24 hours, and videos of continued airstrikes and mortar firings surfaced on social media, despite a Russian declaration that it has ceased its air force operations.



Jaish al-Nasr, a group affiliated to the Free Syrian Army (FSA), accused the Russian army of continuing its assault– with admittedly less ferocity– in the region of Hama. "Compared to the previous days it is nothing, but we consider that they broke the truce," one Jaish al-Nasr official said.

And several videos uploaded by anti-Assad activists purport to show air strikes in Khan al-Sheih in Damascus, Maarat al-Artiq in Aleppo, Ghinto in Homs and Sahl al-Ghab in Hama. One video appears to show a dead victim of an attack lying on a hospital bed with other survivors on beds nearby.

"We were sure that Russia and the regime won't commit to this ceasefire, and that's why after 12 o'clock midnight last night, or early this morning, Russian airstrike and regime bomb shelling didn't stop," said Nagham al-Ghadri, vice president of the rebellion's Syrian National Coalition, on Sunday. "And of course, we called the United Nations, and we informed them about the area and whom, either the regime airstrike or the Russian, so we knew that from the beginning, that this regime, or even the Russian, won't commit to this ceasefire."


Another FSA-affiliated group, Alwiyat Seif al Sham, said two of its fighters had been killed and four more wounded when government tanks shelled them in rural areas west of Damascus.

Yet, while some rebel leaders noted them with concern, neither side seemed prepared to let perfect be the enemy of the good, and both publicly embraced the first sincere pause in fighting since the war began.

One FSA official said that violations of the kind they had seen– should they continue– will ultimately lead to a collapse in the cease-fire. But the White House on Friday said it expected violations along the way, and hoped that an overall decline in the violence would allow for the delivery of crucial humanitarian aid.

"It is unlikely that we’ll be able to judge the cessation of hostilities as a success or failure within the first couple of days, or even the first couple of weeks, because we do anticipate that we’re going to encounter some speed bumps along the way," said White House press secretary Josh Earnest. "There will be some potholes along the way. There will be violations along the way. So that’s why it’s going to require a sustained commitment to implementing this understanding."

The Obama administration hopes that a durable cease-fire may provide the space necessary to explore the viability of a political resolution to the conflict. Syria's rebel groups, the EU, US, Saudi Arabia and Turkey demand Assad leave the presidency, while Russia and Iran consider him the only legitimate ruler of Syria.

Under the last five years of Assad's presidency, since an uprising first took root in Dara'a in March of 2011, between 250,000 and 370,000 citizens have been killed. Half of all Syrians have either been internally displaced or have sought refuge elsewhere, across Europe and the Middle East.

Talks will resume on March 7 brokered by the UN's special envoy to the crisis, Staffan de Mistura, and attended by members of the International Syria Support Group (ISSG)– a group of roughly twenty nations with vested interests in the conflict.

In a midnight press conference in Geneva, as the cease-fire officially took effect, de Mistura said he was "praying" for its success.

"Frankly, this is the best opportunity we can imagine the Syrian people has had for the last five years in order to see something better and hopefully something related to peace," he said.

Only rebel groups that have declared they will abide by the cease-fire are protected from continued assault by Assad's axis, according to negotiated rules of the agreement, which was brokered in Munich earlier this month between Russian Foreign Minister Sergey Lavrov and US Secretary of State John Kerry. Neither side of the war is allowed to attempt to gain territory so long as the cease-fire holds.

The agreement– short of the legal prerogatives and requirements of a formal cease-fire– does not cover the al-Nusra Front, an al Qaida affiliate, or Islamic State. That may complicate the agreement going forward, as several al-Nusra militias are blent in or operate in proximity to other rebel groups.

In one such example, the Syrian Observatory for Human Rights, a monitoring group, said Assad forces dropped five barrel bombs on the village on Najiya in Idlib province over the weekend. The village is controlled by several groups including Nusra Front.

Washington and Moscow have set up a "hot line" to ensure the agreement's success. And Russian and US officials have met to discuss an intelligence-sharing mechanism that will clarify where each rebel group operates.

Should the agreement hold, Assad will maintain significant ground in a war that has dramatically turned in his favor in recent weeks as a result of Russian airstrikes.

In a series of hearings on Capitol Hill this week, Kerry said he feared this cease-fire represents Syria's last chance of remaining a whole and contiguous nation state. The next two months, he continued, will be a test of the "seriousness" of Iran and Russia in negotiations toward a comprehensive end to the conflict– and Assad's ultimate departure.

Should talks fail, the Obama administration is preparing a 'Plan B,' Kerry added. He did not elaborate.

"There are plenty of reasons for skepticism," US President Barack Obama said in his weekly address. "Even under the best of circumstances, the violence will not end right away. But everyone knows what needs to happen."

"All parties must end attacks, including aerial bombardment," he continued. "The coming hours and days will be critical, and the world is watching."

Reuters contributed to this report.