Three civilians were killed and at least 15 others wounded on Monday during Syrian Democratic Forces fire in northern Aleppo, authorities said.
The attack forced dozens of families and factory workers to flee neighbourhoods near the al-Layramoun industrial zone, leaving streets abruptly emptied.
Syrian state media said SDF fighters struck a checkpoint between Shayhan and al-Layramoun roundabouts using machine guns and mortar shells.
Shelling reportedly hit several Aleppo neighbourhoods, killing another civilian and spreading fear through already fragile residential districts.
Al-Razi Hospital was also struck during the barrage, though officials did not immediately confirm casualties or structural damage.
Two children were injured by gunfire near the Shayhan roundabout, while fires broke out in Jamiliyah and Sheikh Taha neighbourhoods.
The Syrian Civil Defense said a woman and a child were killed when a residential home in Jamiliyah was shelled.
It added that two civil defence members were wounded by gunfire near the al-Ashrafieh neighbourhood.
The Interior Ministry described the assault as a surprise attack on joint security checkpoints following an abrupt SDF withdrawal.
Officials said SDF units based in Sheikh Maqsoud and al-Ashrafieh opened fire despite existing security agreements.
The Syrian Defence Ministry said army units responded only to fire sources and later halted strikes to protect civilians.
State television reported the violence led to the closure of the Aleppo–Gaziantep Road, disrupting movement through the area.
The SDF, dominated by the YPG, had signed an integration agreement with Damascus in March, which authorities say remains unfulfilled.
Security operations have intensified nationwide since the fall of Bashar al-Assad’s government, as Syria navigates a volatile transition.