In a major intensification of conflict, jihadist rebels led by Hayat Tahrir al-Sham (HTS) have seized control of most of Aleppo city, as reported by the Syrian Observatory for Human Rights on Saturday.

This marks the first Russian airstrikes on Syrian soil since 2016, targeting areas in Aleppo, Syria's second-largest city.

HTS, a rebel group formerly linked with Al-Qaeda, has been launching a vigorous offensive against Russian and Iranian-supported Syrian government forces since Wednesday.

This offensive occurs amid a tenuous ceasefire in neighboring Lebanon between Israel and the Iran-backed Hezbollah group, an ally of the Syrian government.

The Britain-based observatory, which relies on a network of sources within Syria, has reported a death toll of 311 in recent days, including 183 fighters from HTS and Turkish-backed factions, 100 Syrian soldiers and pro-government forces, and 28 civilians.

Rebels have taken over significant government and police infrastructure in Aleppo, leading to the withdrawal of local authorities from the city center.

An AFP correspondent observed rebels celebrating in Aleppo late Friday, while another saw anti-government fighters gathered in front of the city's renowned citadel.

Beyond their advances in Aleppo, the rebels have also captured the strategically vital town of Saraqib, 40 kilometers southwest of the city.

Damascus has reportedly dispatched army reinforcements to the region to counter the rebel progress.

The resurgence of conflict threatens the 2020 truce brokered by Turkey and Russia for the Idlib region, highlighting the fragile nature of peace efforts there.

The Russian military has confirmed operations against 'extremist' groups, while Turkey has called for a cessation of these bombings.

This escalation further complicates ongoing geopolitical tensions in the region, with serious humanitarian implications for Aleppo's local population, which was a major manufacturing hub in Syria before the war.