TEHRAN (Press Shia Agency) – Syria’s army, backed by volunteer forces, inflicted heavy casualties and damage on terrorist groups in the northwestern city of Aleppo, leaving scores of them dead and injured.

Syrian forces on Friday struck a severe blow to Jaish al-Fath and Jabhat Fateh al-Sham (formerly known as al-Nusra Front) terrorists in Aleppo after heavily pounding their positions in Aleppo, Lebanon’s al-Ahed news website reported.

The clashes came before a humanitarian pause came into force in the embattled city.

On Friday, Russia and Syria started observing a unilateral humanitarian pause in Aleppo to give civilians and militants another chance to leave the city.

The 10-hour-long truce took effect at 0700 GMT (0900 local time), the second such temporary truce announced in the city by Russia and Syria.

Drones filmed roadways and crossing points designated for the withdrawal of militants. Two corridors will remain open for the militants to leave eastern Aleppo and six others are reserved for civilians there.

A similar, three-day humanitarian pause ended last month. Moscow said Thursday Russia and Syria were giving the ceasefire another try in an attempt to "prevent senseless casualties."

Foreign-backed militants, however, have ignored the gesture and used the pause to launch one of their most ferocious offensives last week in order to break an army siege in eastern Aleppo.

Rocket fire on government-held districts killed at least 15 people on Thursday, bringing civilian toll in the area in recent days to 70, according to the so-called Syrian Observatory for Human Rights.

Staffan de Mistura, the United Nations special envoy for Syria, has said the militants had intentionally killed scores of civilians in the west of the city.