Iranian Revolutionary Guards Brigadier General Kioumars Pourhashemi was killed in the Syrian province of Aleppo by "terrorists" linked to Israel, Iran's SNN news agency reported on Thursday without giving further details, Reuters reported.
Militants led by Hayat Tahrir al-Sham on Wednesday launched an incursion into a dozen towns and villages in northwest Aleppo province controlled by Syrian President Bashar al-Assad.
Also, Russian and Syrian war planes bombed the opposition-held northwest Syria near the border with Türkiye to push back the insurgent offensive.
The attack was the biggest since March 2020 when Russia, which backs Assad, and Türkiye, which supports the opposition, agreed to a ceasefire that ended years of fighting that uprooted millions of Syrians opposed to Assad's rule.
In its first statement since the surprise campaign, the Syrian army said it had inflicted heavy losses on what it described as terrorists who had attacked on a wide front.
The army said it was cooperating with Russia and unnamed "friendly forces" to regain ground and restore the situation to what it was.
The militants advanced almost 10 km (6 miles) from the outskirts of Aleppo city and a few kilometres away from Nubl and Zahra.
They attacked al-Nayrab airport east of Aleppo, where pro-Iranian militias have outposts.