Russian-declared ceasefire begins in Syria's Aleppo despite airstrikes
The "humanitarian pause" is the second time Russia and its regime ally have declared several passages open for evacuations.
But expectations were low that either civilians or rebels would leave through the eight passages Moscow said were open, with two reserved for fighters.
Despite the ceasefire declaration, local sources reported two airstrikes on Friday morning, though details remained unclear.
Meanwhile, rebel forces have rejected the Russian initiative, describing it as an attempt to alleviate international pressure.
"This announcement is worthless... We don't trust the Russians or any of their cheap initiatives," said Yasser al-Youssef, from the politburo of the Nureddin al-Zinki rebel brigade in Aleppo.
A similar three-day unilateral ceasefire last month ended with only a handful of people leaving.
Civilians inside besieged east Aleppo expressed fear of crossing into government-held territory, though Moscow and Damascus accused rebels of preventing people who wanted to leave from evacuating.
The UN also failed during the last ceasefire to evacuate injured people, saying it could not obtain security guarantees in time.
Last week, rebel forces began a bid to break the siege on eastern Aleppo where more than 250,000 people remain besieged since July.
In September, Syria's army, backed by Russian forces, launched an operation to recapture the east, killing hundreds of people and destroying infrastructure, including hospitals.
After several days of calm, opposition fighters launched what they described as the "second phase" of that operation on Thursday, sparking heavy clashes with government forces on several fronts on the western outskirts of the city.
Meanwhile, Syria's embattled president Bashar al-Assad relieved himself of all responsibilities in the five year war, instead blaming Islamists and the United States during an interview with the New York Times this week.
"I'm just a headline – the bad president, the bad guy who is killing the good guys," he said. "You know this narrative. The real reason is toppling the government. This government doesn't fit the criteria of the United States."
Hundreds of thousands of people have been killed in the brutal five-year conflict which has attracted the attention of world leaders, international rights groups as well as warring factions which have contributed monetarily or militarily in recent years.
Agencies contributed to this report