Syrian opposition fighters have pushed back government forces around Aleppo in a surprise offensive, rapidly expanded the territory under their control in northwestern Syria. On Wednesday, they battled pro-government forces on the outskirts of Hama.

The lightning assault on Aleppo by the Islamist militant group Hayat Tahrir al-Sham abruptly redrew the front lines of Syria’s civil war.

Syrian rebels battled government forces and allied militia on Wednesday in villages north and east of Hama, a major city whose capture would pile pressure on President Bashar al-Assad. The rebels have staged their biggest advance in years over the past week,