Syria’s antigovernment forces claimed a stunning advance into Aleppo, in a setback for the government in Damascus and its allies Russia and Iran.

Anti-government rebels in northern Syria have launched a sudden offensive in an effort to capitalize on Israel’s efforts to weaken Iran’s regional proxies.

A rebel commander said a fall in Iran-backed manpower created an opening this week's assault. Iran's ally Hezbollah has suffered big losses to Israel.

Syrian President Bashar al-Assad faces the biggest challenge to his authority in years after rebels entered Aleppo, with video shared on social media showing celebrations at their actions in the country's second city.