Islamist groups including al Qaeda's Nusra Front have seized the city of Idlib for the first time in Syria's civil war, fighters and a monitoring group said on Saturday.
By taking Idlib, capital of a northwestern province of the same name, hardline Islamist insurgents now control a second province after Raqqa, the stronghold of the Islamic State group which has been the target of U.S.-led air strikes.
Sunni Islamist groups have formed an alliance which includes Nusra, the hardline Ahrar al-Sham movement and Jund al-Aqsa, but not Islamic State, their rival. They launched the offensive to capture Idlib city on Tuesday.
Syrian officials could not be immediately reached for comment. State media said fighting continued and the army had managed to halt the insurgents' advances on the northern, eastern and southern sides of the city.
"The army is fighting fierce battles to restore the situation back to what it was," state television said, adding that the army had killed hundreds of fighters.
Groups taking part in the offensive to seize the city posted videos on the internet showing fighters roaming the streets. Voices in the videos said they were in the center of the city.