BEIRUT (AP) — Fierce fighting in Syria’s contested northern province of Aleppo killed at least 21 rebels on Monday as rockets slammed into a government-held district in the provincial capital, killing nine people.

The clashes, which erupted after midnight Sunday and continued through the day Monday, also left at least 30 soldiers dead or wounded, said the Britain-based Syrian Observatory for Human Rights. The Syrian government does not publicize its casualties in the war.