A general view over damages inside the Umayyad Mosque in the eastern neighborhoods of Aleppo, Syria, December 13, 2016. [Photo/IC]

DAMASCUS - A truce for evacuating rebels and their families from rebel-held areas in Aleppo city in northern Syria has failed, and both warring sides resumed fighting, sources in Aleppo told Xinhua on Wednesday.

Both sides are exchanging mortar fire, hours after an anticipated evacuation of rebels was delayed for unknown reasons, sources said on condition of anonymity.

Sources said the government busses were ready to transport the rebels through the Ramouseh road out of Aleppo toward the western countryside of the city.

Local media outlets accused the rebels of breaching the truce, saying they attempted to attack military positions, when the army responded with firepower, and thwarted their attempt.

Also, the Russian-run monitoring center of Hmaimim in Syria's northern city of Latakia said that the rebels were the ones breaching the truce, by repositioning their forces and resuming the battles against the Syrian army.

It added that the Syrian forces repelled the attacks.

For his part, Russia's Foreign Minister Sergey Lavrov said that calls for truce in Aleppo aim to give a respite to the rebels to allow them to take their breath for another fight.

With the renewed shelling, he said the rebels remaining in eastern Aleppo can resist for two or three days at the most.

Meanwhile, the state-run TV said one man was killed and 16 others wounded by mortar attack on a marketplace in the Khalidiyeh neighborhood in government-controlled part in west of Aleppo.

It added that six others were killed by similar attack on the recently-captured Bustan al-Qaser neighborhood east of Aleppo.

On the opposition side, activists said the Syrian forces were the ones breaching the truce, by targeting the rebel-held areas with tens of mortar shells and artillery shells.

Activists said the shelling was random in the rebel-held areas of Mashad, Ansari, Salahuddien, Mashad and Sukari.

The Syrian Observatory for Human Rights monitor group also confirmed the falling of the truce for the rebels evacuation, saying intense battles broke out in Aleppo again.

With both parties trading barbs, it was clear what derailed the operation in Aleppo, where the Syrian army has become in control of 99 percent of the rebel-held areas in eastern Aleppo.