The Syrian military on Tuesday urged rebels to pull out of east Aleppo and allow civilians to also leave, as it pressed an offensive to recapture the city's opposition-held sector.
The army, which has besieged the east for months, also demanded that rebels distribute food to civilians, while calling on residents to cooperate with its advancing troops.
The military airdropped leaflets with a picture of a green coach like those used in the past to transport civilians and rebels from areas retaken by the government.
"To those involved in carrying weapons, we stretch out our hand to you. Reserve your place before it is too late," the leaflets read.
The picture showed the coach on a road marked "the path of salvation".
In a separate statement carried by state media, the army accused rebels of using the 250,000 civilians still in the east as "human shields" and demanded they be allowed to leave.
"Permit those citizens who want to do so to leave, stop using them as hostages and human shields, clear the mines from the crossings identified by the state," the army said.
Syria's government and its ally Moscow have said several crossings are available for civilians and surrendering rebels to cross from east Aleppo, but they accuse opposition fighters of preventing departures.
The statement urged "brother citizens in east Aleppo to cooperate with the Syrian Arab Army", while stressing its "firm commitment to their security and safety".
The army accuses rebels of hoarding food in the east, where aid rations have run out after nearly four months of government siege, and said Tuesday that fighters should distribute rations.
"We call on the gunmen in east Aleppo to open their warehouses and distribute food rations to those in need," the army said.
On Monday, UN humanitarian chief Stephen O'Brien condemned the use of sieges in Syria, saying nearly one million people across the country were under blockades, most imposed by the regime.
"Civilians are being isolated, starved, bombed, denied medical attention and humanitarian assistance in order to force them to submit or flee," he told the UN Security Council.
As the army advances in east Aleppo, its leadership announced the formation of a new voluntary battalion tasked with "eradicating terrorism, fighting alongside the rest of our heroic army and allied factions."
There were no details on who would man the battalion or when and where it would fight.
Syria's army has relied heavily in the fight against rebels on local pro-government militias as well as Lebanon's Shiite militant group Hezbollah and forces from Iran and Russia.
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