The Syrian military said on Thursday a unilateral ceasefire had come into force to allow rebels to leave the besieged eastern part of Aleppo city in a move that the rebels said was part of a psychological campaign to get them to surrender.



State media earlier said the army had opened exit corridors in two designated areas in the Bustan al Qasr quarter and near the Castello road in northern Aleppo where waiting green buses were shown on state television.



Intensified Russian and Syrian bombing of besieged rebel-held parts of Aleppo have knocked down scores of hospitals, bakeries and water pumping stations in a stepped-up offensive that has killed hundreds of civilians in the last few weeks.



The Syrian military said on Wednesday it would observe a temporary ceasefire to allow trapped civilians to escape and said it had pulled back to enable rebel fighters to leave the city via two designated corridors.



"We guarantee a safe exit, save your families," an army loudspeaker blared near an exit corridor shown live on the pro-Syrian government Lebanese news channel Mayadeen.



Rebels say the goal of Moscow and President Bashar al-Assad's government is to empty rebel-held parts of civilians so they can take over the whole city.



The rebels say they are preparing a large-scale offensive to break the siege of Aleppo and say the Russian air force has failed, despite a relentless bombing campaign.



They say the army and its Iranian-backed militias are finding it harder to make headway after initial progress on the outskirts of the city that allowed the army to tighten its grip.