DAMASCUS — Israeli airstrikes after midnight Monday killed 12 pro-Iranian militias in Syria's northern province of Aleppo, the Syrian Observatory for Human Rights said.

The militias, consisting of Syrian and non-Syrian nationals, have a significant presence in the area surrounding the city of Aleppo, it said.

The attack hit several sites in the countryside of Aleppo, mainly in the town of Hayyan northwest of Aleppo. Several explosions were heard across the city

READ MORE: Israel launches airstrikes on Syrian sites near Damascus

The attack hit several sites in the countryside of Aleppo, mainly in the town of Hayyan northwest of Aleppo. Several explosions were heard across the city.

The observatory noted that the attack comes as part of an escalation of Israeli attacks on positions held by the Lebanese Hezbollah and Iranian militias in Syria since last month.

READ MORE: Israeli strikes on Syria kill dozens, security sources say

Meanwhile, the Syrian Defense Ministry confirmed that several individuals were killed in the Israeli aggression targeting points near Aleppo.

Israel launched air attacks on May 29 on Syria's central region as well as the coastal city of Baniyas, killing a child and injuring ten civilians, according to Syrian state media, reports Reuters.