Aircraft dropped seven barrel bombs and other explosives late yesterday on the IS-held town of Al-Bab northeast of the city of Aleppo, the Syrian Observatory for Human Rights said.
Regime air strikes have repeatedly targeted Al-Bab, a stronghold of the jihadist group that has seized control of large parts of Syria and Iraq.
Syria's military has increasingly resorted to using so-called barrel bombs, which rights groups have condemned as a particularly indiscriminate weapon that often kills civilians.
The Britain-based Observatory, which relies on a broad network of sources in Syria, and local activists say the regime has stepped its use of the crude weapons in recent weeks, as international attention focuses on the fight against IS.