By Halit Suleiman

ALEPPO, Syria

At least 25 civilians were killed Tuesday in regime airstrikes in Syria’s northwestern city of Aleppo, according to a pro-opposition Syrian civil defense official.

Speaking to Anadolu Agency, Ibrahim Abu Laith said regime warplanes had targeted civilians as they attempted to flee from the Al-Myassar district to the Bab al-Nairab neighborhood in opposition-held areas of eastern Aleppo.

"At least 25 were killed -- mostly women and children -- and scores more injured," Abu Laith said. "The regime is striking at everything that moves."

"The situation in the city is extremely tragic," he added.

Since mid-November, more than 643 civilians have been killed -- and hundreds more injured -- in regime attacks on eastern Aleppo, according to figures released by local civil defense officials.

Syrian regime forces have recently stepped up their attacks on opposition-held parts of eastern Aleppo in an effort to retake the city and advance on Idlib, one of the Syrian opposition’s last strongholds.

The fierce bombardments have forced hospitals and other medical facilities in the war-battered city to cease operations while most academic activities have been completely halted.

Syria has been locked in a devastating civil war since early 2011, when the Assad regime cracked down on pro-democracy protests -- which erupted as part of the "Arab Spring" uprisings -- with unexpected ferocity.

Since then, hundreds of thousands of people are believed to have been killed and millions more displaced by the conflict.