Syrian rescuers and a war monitoring group say 37 people were killed in airstrikes in a town in the eastern Ghouta region near the capital, Damascus, just hours before a cease-fire went into effect after midnight.
Russian Federation struck on Friday a new agreement with an opposition faction in Eastern Ghouta to evacuate the wounded, fighters and civilians to the opposition-controlled northwestern province of Idlib in line with talks launched with Jaysh al-Islam to reach a deal in Douma, the last opposition stronghold near Damascus.
Eastern Ghouta was once the opposition's bastion on the edge of Damascus, but beleaguered rebels are now left with less than 10 per cent of their onetime stronghold.
The government of President Bashar Al Assad and its ally Russian Federation have implemented a "leave or die" strategy with air strikes on rebel-held areas as they look to end six years of opposition control.
Rebels completed a negotiated withdrawal from one Ghouta town on Friday and a similar deal was reached the same day for Faylaq al-Rahman rebel fighters to pull out of a second area.
The agreement will involve clearing a southern stretch of territory that includes the towns of Zamalka, Arbin and Ain Tarma.
Faylaq al-Rahman group, which agreed to a ceasefire late Thursday following another wave of deadly air strikes, confirmed the agreement.
Syrian state news agency, SANA, reported that more than 4,000 people left Ghouta on Friday.
Harasta's evacuation came as part of a deal negotiated by Russian Federation, which has played a key role in the deadly offensive launched against the besieged enclave on February 18.
The group added that opposition fighters and their relatives who decide to leave eastern Ghouta will head to rebel-held parts of northern Syria while civilians who choose to stay will be guaranteed safety.
Each one of the three pockets has come under intense bombardment, essentially forcing the rebels that control them to sue for an evacuation.
Rebels stand together as they wait to be evacuated, outisde Harasta in eastern Ghouta, in Damascus, Syria March 23, 2018. "We couldn't even find fodder to eat".
Retaking eastern Ghouta, a sprawling semi-rural area which had escaped regime control since 2012 and lies within mortar range of central Damascus, was made a priority by the regime this year.
At least seven people were killed in a car-bomb blast in Syria's northwestern Idlib city on Saturday, according to a local civil defense official.
The evacuation will take place on Saturday at 9:30 a.m. (0730 GMT) after the rebels hand over maps of the tunnels they dug and mines they planted in the aforementioned areas.
"The one thing they got was that they were able to leave without being killed", said Nawar Oliver, an analyst at the Turkey-based Omran Centre.
An evacuation to Idlib could potentially be most damaging to Jaish al-Islam, however, due to their strong local ties in Eastern Ghouta and having no connections with groups in the north.
The government's crushing offensive killed almost 1,500 people and wounded more than 5,000, according to opposition activists.