Members of the Syrian Civil Defence, known as the White Helmets, search for victims amid the rubble of a destroyed building following reported air strikes in the rebel-held Qatarji neighbourhood of the northern city of Aleppo, on October 17, 2016. (AFP/Xinhua)

DAMASCUS, Oct. 20 (Xinhua) -- Syrian military helicopters dropped hundreds of thousands of leaflets over rebel-held areas in the northern city of Aleppo on Thursday, detailing exit routes for civilians and rebels to leave, a military source told Xinhua.

The maps highlight six routes for civilians who want to leave the rebel-held areas in eastern Aleppo into government-controlled ones, and two routes for rebels who want to evacuate to other rebel-held areas in the countryside of Aleppo, the source said on condition of anonymity.

The leaflets also include a call on the rebels to "not waste the chance" and to leave or lay down their weapons, offering help for those who do want to leave.

A three-day humanitarian truce declared by the general-command of the Syrian army started Thursday, effective from 8 a.m. to 7 p.m. local time.

The general-command urged the rebels to lay down their weapons and take advantage of a pardon issued by President Bashar al-Assad for all rebels who surrender themselves to the Syrian army.

In a statement, the general-command said it had detailed information on the whereabouts and positions of the rebels in the eastern part of Aleppo city, warning that "any armed man who doesn't take the chance of the declared truce will meet his doomed fate."

The evacuation of ultra-radical groups, mainly the terror-designated Jabhat Fateh al-Sham, from Aleppo, is a key condition set by Russia and the Syrian government for easing a military offensive against eastern Aleppo.

The evacuation process started on Wednesday evening, with some armed men along with their families leaving eastern Aleppo.

Another batch of armed men also left via the Castello road in northern Aleppo, but other rebels seem to want to thwart the process, with the Syrian national TV and military sources reporting several shelling and sniper shots by rebels on routes the government identified for the evacuation of civilians.