21 civilians killed in Syria regime, Russian airstrikes

At least 21 civilians were killed and scores injured Friday in airstrikes carried out by the Syrian regime and Russian warplanes in the northern city of Aleppo.

The strikes hit the Bustan al-Pasha, Karm al-Beik and al-Sukkari neighborhoods, according to a local civil defense official.

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

Since then, more than a quarter of a million victims have been killed and more than 10 million displaced across the war-battered country, according to the UN.

The Syrian Center for Policy Research, however, puts the death toll from the six-year conflict at more than 470,000 people.